Condition between 1st eleven and bench players is not equal.

Even if I substitute player after 15' it is still high chance that the second guy will lose lower amount of energy than the starter.

Isn't it based on actions taken during the match?

I remembered in world cup Italian senior team sang national anthem with heart ♥️ 

In KOB that's 1 energy for shouting😆. Sorry but the energy of the starter will not be same even if you sub before the kickoff  as long the players are Italy nationality lol😝

Some of the difference may be due to fatigue or NF