Devolik, I don't know, on normal difficulty, with a fast-paced strategy, almost all enemies within a small/low range can be cleared in the first week without significant losses. Losses sometimes occur against archers, but it's debatable. On hard difficulty, it's not as easy, but if you think about who and when to attack, it won't be too difficult...
Friends, it's simple arithmetic. If 4 players constantly spend even 4 minutes per turn (and in manual battles, it can be even longer), then in total, a turn will take 16(!) minutes. In a gaming week, that's 112(!!) minutes. In a month, it's 448(...). That's 7.5 hours. For some gaming month... it's not even funny.

And then, notice, I didn't write "forget about these manual battles." I myself don't like skipping battles and I feel bad about every lost unit. But time is more valuable, especially when playing online.