There should be a bug in idle causing approximately 8-16 times drafting armies when using application and web at the same time after closing aplication and refreshing it got fixed and become normal but could not reproduce and did not tried it extensively so i cannot say what caused it.
Sincerely.

Sometimes i get spikes after buying huge amounts of mercenaries. Did you?

I was mostly drafting 8-10M before buying mercenaries, but now I'm getting 45M

Yes it could be. If i remember correctly, after my tech was done i bought all the mercenaries that could be the reason for spike.

when using application and web at the same time

Are you saying that you play the same level from mobile and from browser in parallel AT THE SAME TIME? Don't do this!!! This might corrupt your level data. You can only run the game from one platform at a time. Otherwise, the different platforms might try to sync their progress and totally screw you up. Your level progress might even get lost in the process.

I am not playing at the same time. It just happened i forgot application running when i was on the computer.

Again, don't know for sure, but this might cause you losing all your level progress at some point. One player reported that after a power outage (and as a consequence a manipulated system clock) the game hadn't let him continue the level because it detected something that almost looked like a cheating attempt (so or similarly, the message said). I'd be try my best to avoid such scenarios.

But then again, this might have been the problem with your observation. Perhaps the game behaved strangely because some actions were taken on one platform, others on the other, and one of the game instances was doing its best to interpret the differing information. The result were strange draft sizes. If this was the case, congratulations that only the drafts were messed up.