Also the
wiki can be of some help there is a description of all the units and their strengths and weaknesses:
The key words in the title were "in-game". People are jumping into the game and are feeling overwhelmed. If I were feeling overwhelmed, I would prefer that the game itself provide help, instead of me having to visit a third-party website.
Plus, at the moment, the wiki is just copied verbatim from the manual, so it doesn't offer anything the manual doesn't.