Action timer in combat.

15-20 minutes for the initial phase + 30 seconds for each subsequent action (you can add a minute in extreme cases if the remaining time is burned after the turn). If an action is not performed, the unit goes into defense, or, again, if a technical change allows, the AI can make the unit's turn (although I think this is completely unrealistic, since there is no auto-battle in player battles), and this timer is more than fair!

P.S. If you remember the "past," when switching from the Sod's law timer to the chess timer, there were also many skeptics and opponents, especially those who were obviously slow, and we had to wait 20-25 minutes for them in a match with a basic 6-minute timer. We got through that stage, but we need to move forward! It is these aspects that will lead to an improvement in the esports aspect of Heroes, and not your "balance" changes and super-hero versions.