I always saw Fallout combat very similar to XCOM one - things flying around, and sometimes shit happens.
Grenade crits, and running to 1 hex to get impossible damage bonus is just weird in my opinion.
Though 1 hex bursting was big problem ever, it was always rather weird feature - at least compared to something that would be far less binary.
Anyway even with great balance on numbers or tactics, you also need some balance in game economy - so that you don't get 200 BA from botting for a week, but you don't spend whole game in leather jacket either.