We'll see what the story says, but 3 new armors seems excessive and a bit driven by marketing. The Mark 4 looks like a slight variant of the Mark 3, so hopefully the story justifies that one a bit. Mark 5 and 6 make some sense, 5 is really just a portable, crude suit, and 6 is likely the, I got my ass handed to me and need something better, suit. Mark 4 is the only one that, for now, seems forced.