Mercenary Recruitment Question:

[Nick_K]

Movement of units into friendly provinces happens before combat though. If I'm facing a big AI attack and want to recruit mercs, I won't recruit them in a province I might lose. Instead, I recruit them in a safe adjacent one then move them into the contested province next turn. That way I also get them to hold off further AI expansion if I lose.
Of course, if you want to attack with the mercs, recruiting on the borders is best.