I think having nations send you soldiers is a good improvement over the original, its a definite incentive to take care of your soldiers...
However, would there not be the chance that you could "buy" mercenaries - at an elevated price perhaps, to supplement your official stocks?
When I get more than 19 soldiers, scientists, workers or medics, I can't scroll down the list to see more... It seems I can only ever see the first 19 regardless of whether I have 30 or 40 staff given to me at any time.