GURPs is a great RPG, but will quickly bog down with more than a handful of characters and enemies per side. It would do a good job for small unit actions, like Commandos or Resistance focused games, and if you add in GURPS Supers or Wierd War you can have extra fun in a WW2 setting.
For larger games that still have an RPG Lite element you may want to consider the NUTS! system from Two Hour Wargames. While mainly a WW2 skirmish system, there are the optional "Chocolate and Ciagarettes" rules that let you create a "Star" that stands out from the "Grunts, and the Star can have attributes (Crack Shot, Coward, Looter, Brawler, etc.) that effect game play and a light set of stats to do other things. These are FIT, SAVVY and PEOPLE, and are used on different challenges and tests. Climbing something might be a FIT test, speaking with someone to get information or to wheel and deal would be a PEOPLE test.
There are campaign rules that allow you to increase your Star's experience (called REP), gain new equipment, gain or lose rank, awards/medals, and the downside like getting Combat Shock and so on.
You can get a sense of the game from this recent after action report: link
explores another variant in the European Buildings range.
