Well, I think the basic gist of the conversation is that the Arcade card doesn't add anything that aids in downward porting of SGX (and arcade, for that matter) games to regular PCE. Hence, Arcade card Strider CD major fumbletitude.
It just has loads and loads of storage for animation frames, BGs... but the poor PCE still has to manage this with its (major, for '90s arcade games) tile, 1 BG, and 16 (on a line) sprite limitations.