I'm not sure, there is very much use for that to be honest. If you are short on gold, your aim usually is to level up your main DPS since all others aren't contributing DPS after you unlock the last ability. If you aren't, levelling all vs. levelling up to twelve or thirteen crusaders until they cap doesn't make very much difference if at all.

There are only two crusaders in any formation that EVER need to be constantly leveled up - your DPSer and your tanker. And the tanker is very, very, VERY rarely something you should have in your formation to begin with. Unless you're using a formation that uses 2 DPSers, you should only bother with leveling up one crusader until just before resetting.

Also, like Vingummi said, the difference between "all crusaders" and "only active crusaders" would result in almost no difference in levels. It would be a matter of a few levels at most.

and if you think it will not be needed, you will always be free to not buy it and save the idols ....

bigfat, OCD is an actual disorder. That's what the "D" stands for. Actual OCD is not some minor, petty inconvenience. Vingummi's comment is actually closer to what would be best for OCD, since someone with the disorder would lean away from any automated system, especially one that works in bulk. OCD is the polar opposite of efficiency. It is not a matter of whether or not the game "needs" such a button. It is that the game would have literally no use for it. It would be dead weight; lines of code, time, and effort put into applying a mechanic that has absolutely no use.

As for talent costs, I've got over 600,000 unspent idols. Prices don't mean much anymore. This is what the forums are for. You posted your suggestion, and now more-experienced players (that is not meant as an insult, by the way) are giving you feedback on your idea.

Saying you would enjoy the game more is all that is needed to validate the suggestion hinges entirely on the quality of your judgment on the matter, which has been debunked. You're asking for a button that does the same thing as something that already exists and treating it like some great idea. Yeah, a "level all" button is a great idea...that already exists. If using the level-all button would normally bring "Crusader A" to level 500, then a level-active button would bring that same crusader to maybe level 510. Maybe. Since apparently the words haven't sunk in yet despite how many times they've been said, I'll say them again: What you're asking for already exists. Just not in the EXACT capacity you want it to, to no effective difference.

I'm not trying to be rude or offensive, but you just won't take "No" for an answer.