Not much to say about Almain Rivet, except for the fact that, perhaps because they were mass produced, there are no vambraces, couters, or greaves. Fitting problems, maybe. Though it's probably got more to do with the fact they were mostly made for Pikemen, who usually did not wear that stuff.

I personally like three-quarter armor because of its long, one piece tasset-fauld-cuisse mix.

As for Landsknecht clothing, afaik they dressed as such as to just be conspicuous and show off their independence (said clothing was often of noblemen, and Maximilian decided to bend the peasant-commonfolk clothing laws for them, saying 'Let them have some fun').