I've seen a lot of people complaining about difficult objectives, or getting the achievement for reaching area 1000 (which I am nowhere near close to), so I thought I'd put together a helpful guide for pushing further than your idol count would suggest you could. It's still much more efficient to only go as far as the monsters are easy, and then reset, but if you need to push, here's how.

On regular levels, the secret is to get maximum power out of Merci's Deflect Evil ability. (Petra's splash damage has a higher floor, but a lower ceiling. You're going to spend a lot of time stuck on the ceiling.)

What you need, aside from Merci and a solid tank, is some means of increasing your DPS based on the number of monsters attacking you. Any one of the following Crusaders will do:

1) Wendy the Witch
2) Groklok the Orc
3) Jack O'Lantern
4) The Metal Soldierette

If you're not yet reaching the level cap on all your Crusaders-- something else I am far from accomplishing-- you also want a Crusader that increases your Gold Find based on the number of monsters attacking: Greyskull the Pirate or the Dark Helper.

Best case scenario involves using Wendy with Groklok or Jack, because both effects stack. Set your tank up with a healer and a crusader that grants damage reduction, make sure Merci is in the formation, and watch your DPS soar to ludicrous heights as more and more monsters pile on. Either the monsters will overwhelm your tank (which takes a ludicrous number of monsters) or they will reach an equilibrium where you kill them roughly as fast as they spawn.

This strategy does not work on bosses. To deal with bosses above your weight class, you need to maximize the damage you deal to a single target. This means a combination of raw DPS, click damage, and crusaders with an ability like Karl the Kicker's ability to deal a percentage of DPS to a single target periodically.

First time I posted this on the Facebook page, I suggested Ghostbeard's Greed as the best formation for this strategy, but it can work on any formation-- if you're pushing for Area 1000, your best bet is obviously World's Wake.

Assuming access to all Crusaders and reasonable gear, here's the best standard formation (top to bottom):

Front column: Jack O'Lantern
Second column: Khouri, Dark Gryphon
Third column: (empty slot), the Exterminator, Merci
Fourth column: Ilsa, Wendy, Veronica, Mindy

Jack O'Lantern. of course, increases global DPS by 10-20% per monster attacking him, and the second column is all about keeping him alive.

The empty slot in the third column is to isolate Ilsa, so she's only adjacent to Wendy-- in addition to the DPS boost from Jack, she adds twice the value of Merci's Deflect Evil splash damage and drains half of Wendy's DPS to add ten times that amount to her own.

The reason we're using Veronica is that her gear, unlike Jim's, increases her column buff and she gets an extra boost from the Exterminator. Mindy copies Veronica, adding more DPS to Wendy and Ilsa, and Merci to improve splash damage to 150-200% of DPS, depending on her gear.

Then, when we get to bosses that this formation doesn't kill, we swap out for our "boss formation":

Front column: The Metal Soldierette
Second column: Karl the Kicker, Princess
Third column: Bush Whacker, Fright-O-Tron 4000, Montana James
Fourth column: Robo-Rudolph, the Exterminator, Veronica, Mindy

Robo-Rudolph and the Exterminator are 20th and 21st slot DPS Crusaders, respectively, that both increase their DPS based on the number of other robots in the formation. Bushwhacker is adjacent to both of them for maximum click damage.

Princess doesn't meet any of the normal criteria for this formation, but here she adds seven separate DPS boosts--- her necklace, her first four upgrades, and activating Montana James' Damsel in Distress ability, which Mindy is copying-- plus enhancing Swordplay and adding the Firestorm ability. She is strictly better than RoboTurkey.

Here, Mindy is copying Veronica and Montana James, gaining two more "punt" attacks (total five), applying a second instance of Precise Aim and Damsel in Distress, and increasing The Metal Soldierette's damage reduction.

Also, note that your bottleneck might not be how tough your tank is-- I have a pretty gnarly gaming machine, and the game starts lagging really badly when there's over 200 monsters on the screen. Luckily, I was able to put another 25 levels on my primary DPS (Hermit), which brought the monsters down to a much more reasonable 54-55.

Nice that you figured all of this out fairly early. If I'm nor mistaken, you started this game fairly recently. Putting this much thought into the game this early is uncommon, I'm sure. Kudos. If I may add some other helpful hints, as someone who has many talents maxed...

Other DPS-buffers to consider...

Dark Queen: Depending on if you've got her well-geared, if you manage to isolate her next to a single crusader (even two should be fine), she gives a huge buff, and one of her rare gears gives 3% click chance, which translates into an additive 150% DPS from that stat.

Littlefoot: Seriously, if this girl isn't on your team, you either do not have her or you are playing wrong. Her "Growing Up" ability is phenomenally useful. Of course, again, only so long as you have certain talents maxed. She is fairly underwhelming otherwise, but once you reduce XP gain to only taking 30 minutes, she gains "Growing Up" stacks crazy fast and can give a global DPS buff in the multi-hundreds of percent. 10% per stack is already nice, but that is without being boosted. Her epic gear brings that up to 20% per, which leads to amazing results. She also works well as a tank. Although there are better tanks, they don't generally give the DPS buff she does.

Anything in the "Artaxes" slot: This obviously depends on your gear. These guys can buff your DPS pretty intensely (my Bubba gives 375% to the column behind him), but they also give the "Savage Strikes" ability which can give you a very useful temporary DPS buff for dealing with troublesome bosses. This buff naturally also helps out Merci's "Deflect Evil" ability, making everything die all at once. If you've been tanking to build up a wall of enemies, it is therapeutic watching all their health bars drain simultaneously.

Mr. Boggins: Only if your DPSer is an animal. His "New Students" ability gives a huge base buff, but then also boosted by human crusaders. Also, having an animal DPSer would let it benefit from James' "Just in Time" buff.

Proof of Concept: http://steamcommunity.com/sharedfiles/filedetails/?id=858393524

I'm still on the weekend buff, so Drizzle is providing Hermit and Groklok 95% damage reduction; Gryphon is there strictly for the bonus health, because I wiped at 589 and at 594, with Groklok providing over a 2000% DPS bonus.

I'm clearing bosses by applying triple DPS and critical buffs, then dropping a magnified firestorm and a savage strikes.

I have 14,909 idols. If I'd joined a month earlier, I'd have the Dark Helper and everyone would be at level cap by now.

Yeah. Merci's splash damage is strictly better with a proper tankline... but the key point here is that if you use Petra instead, she's a 19th slot primary DPS who will be earning XP during your regular grinding... meaning you could potentially have Bush Whacker adjacent to a capped 19th, 20th, and 21st slot DPS, at least one of which with XP.

As I understand it, the logic behind advancing a single primary DPS, or two complementary DPS, is cost-efficiency. Since I'm talking about area 1000 runs, I'm assuming that everyone is already at level cap and that the issue is less cost-efficiency and more about eking out every last possible scrap of DPS and click damage.

It's still better to pile on more support if possible, but your options here are somewhat limited as well.