Simple: characters who weren't present when combat started should take time to actually reach the combat, represented by them missing the first turn of combat. Realistically they should be entered into combat regardless of their location, but this could result in them having to spend many (possibly 5-10 or more) turns just dashing toward the combat. Allowing them to enter combat with only a 1-turn penalty is a compromise.
Oh no. That doesn't work towards that in the game. Your characters are often forced to skip first turn even if they were 5 steps away.
