Put in a handicap for the first 20, then 80 turns, so conquering unclaimed land for the first 100 turns is easier.
Effective enemy strength is reduced by 1 during the first 100 turns.
Effective enemy strength is halved during the first 20 turns.
The first does apply during the latter(subtract 1, then halve).
It should be a lot easier to get started.
Please try it out and give feedback.