Strategy-RPG
Tactical-RPG
These two terms are often used interchangeably (i.e. games like Fire Emblem, Final Fantasy Tactics, Jagged Alliance and so on) are often referred to as SRPGs. These are games where the brunt of the gameplay is focused on tactical gameplay, where you have a (potentially) larger groups of soldiers, and where the individual soldier is not as important. It's basically a tactics game, with heavy RPG elements. So if Battle Isle had persistent units that level up, it would be an SRPG/TRPG. If you want to be picky, most of these are TRPGs, and there are very few SRPGs out there, but that's not how the term is used.