Quote Originally Posted by Patch Notes
Infantry Units
There are THREE new infantry units being added in this patch. We have Pvt. Oliver (British), Pvt. Rascal (US), and Pvt. Otto (German). They have different rarities and when used in upgrading, give a lump sum of exp. For example, Oliver as a 3-star cat gives 2,000 XP flat and Pvt. Otto as a 5-star cat gives 50,000 XP! You will have to construct these units through the schematic system – which means new expeditions as well. Fight Invasions now on Tuesdays, Thursdays, and Saturdays to get expedition maps. Training maps will give you the chance to earn Infantry Rations and Infantry Rucksacks, which combine into different tiered cats! Get going!
So these new cats are just exp fodder units, like in many other games.