Can't go wrong with this classic tactical rpg strategy game with realistic elements from that time period, such as the ai following sounds to each mercenary having not only having different statistics, but different attitudes and reactions to certain mercenaries and actions. Not all mercenaries can be hired at the start, but as the game goes on, more will be willing to work for you, for the right price. Those who played XCOM should give this a try, even though this is a dosbox port of the original. The price may make a little sense since its two games in one download.
And here's a tip: Be sure the first mercenary you get is Ivan, me speaks Russian in all versions and is a bit expensive, but his marksmanship more than pays off, and he is one of the mercenaries that will work for you in the beginning.