Auto recovering generals - A Giant Battle

I am currently doing A Giant Battle adventure and I use a lot of 1MMAs attacks to progress. And on few ocasions I've sent MMA attack and then after a while I check game and few of them are ready to action while the rest is recovering with more than 1 hour to recover(it applies to other generals aswell).

In my most recent Battle reports I see 50 minutes difference between 2 MMAs waves(they don't have instant recovery skill and they died many times already in this adventure).

They attack camp, they kill units in enemy camp, they die in fight. Though I've never been watching game to notice the moment they come back to their camp and be ready to action. I am not sure what triggers that as sometimes it happends and sometimes it doesn't.

If you check my logs(if you have easy access to that kind of data) from few hours before I wrote this post then I guess that you might see what happend.

[Edit]With Nusala(She's the one with fast recovery skill) I made a little bit of testing and every time I send her and then close the game, wait enough time for her to attack and come back to her camp she will be ready for next attack.