Starting first already gives you the advantage of staking out your territory and being the first to trade cards, why should it also give you the bonus of having more reinforcements at the beginning.
With the continent bonus you could just make continent bonuses not part of the troops calculated on initialisation, though I don't see the big deal about them, this is no different than the person who takes the first turn landing a bonus, because nobody will have time to steal the bonus of them.
This suggestion was provoked when I played a 6 player World 2.1 manual game. Everyone started with 18 territories, meaning 6 reinforcements, but because it was manual, by the time it was my turn I ended up with only 3 reinforcements, which is a significant difference. With 6 men you could place them all on your manual stack, auto attack a neighbouring stack and should win, basically meaning game over for the other player or you could invest in another area, something really not viable with just 3 troops.