how is this different from the 16 other events and 17 times they have been run a second time and the one shot one time special event?
you want ep on them, then you work to get ep on them, otherwise do as everyone else does and use them without ep or with little ep.
boo hoo.

'Sharing is Caring' costs you 43,480 talents to max as far as I can tell. Use those idols and 'all' you need to do is to bring all bench slots to an equal level. Maybe, checking the talents is what would be recommended for you to do ASAP?

300 and 400 EPs are required to recruit previous T2 crusaders and getting gear for them. Even for veteran players, those missions are hardly possible to succeed with 100% and they are designed with this intention.

Now, what I would recommend for every newer player: Rather get your crusaders' EPs up than use them in your formation. Especially those with more rare or more than average tags. There are some great web pages you can check to get to know those crusaders. Especially those with multiple races or genders so you can use them to fill the more complex tags' requirements. Also, try to get multiple crusaders to lower levels at the same first. Some of the missions only need 50 and 100 EPs before the big ones with 300 and 400. Try to do those first. Since you will spend most of your gaming time farming for idols, try to use a formation which consists of crusaders you don't constantly send off on missions.

Plus, if you calculate to need half a year for one crusader to get him or her 400 EPs, I would agree that this is taking too long. I got Zombie Winter over 400 yesterday, Beary McBearface is on 350-ish. So you can get them up quickly, even as a newer player since all but three are without EP requirements, all but four without gear check. For me, I get the majority of EPs through the shorter missions. Make use to send a crusader off for 5 or 10 minutes and right away again for another of those shorter missions to get 2 EPs within half an hour. Only use the longer time EP missions when you know you have a longer break (i.e. end of the day). Try to find perfect matches for certain EP missions. If you want to get EPs for a crusader in your preferred formation, either do so in very short missions during parts of your objective you don't need them (healer early on in the objective), or over night in case you don't auto progress while sleeping. Use your time offline to your advantage rather than something blocking you.

Sharing EP for missions is an idea, but not one that I would put as a high priority and sounds like a non-starter based on Erika's comment about "why it uses".

I am happy getting EP on each 'sader according to my priorities for them. 'Saders with the most tags (6-7) or with rare tags (Demon, Dwarf, Angel, Dragon, Alien, Orc, Leprechaun, Clicker) or with more high-level gear are the top priority. The high-EP missions also tend to require high-level gear, so which 'saders have the best gear is another factor about whether to send a 'sader on a mission when they already have 200 or more EP.

I don't really worry about EP for the purpose of achieving objectives. Earlier in my gameplay I did, but as I get Sharing is Caring ranks (still not maxed, maxing talents is expensive and most talents have diminishing returns) and more 'saders in more slots, adding 1 to 10 EP is a negligible effect on DPS, especially for non-DPS 'saders.

Thinking about it, if I didn't have 400 (or higher) personal EP missions or new 'saders somehow got a share of EP to be used on missions, then I'm not sure whether I would continue to send them on EP missions. I'm sure that I could be happy with this, but it would mean the EP missions would be yet more game functionality to ignore, like Gold missions.