You both make good points, but unlike pushblocking most physical attack assists (where the character will just go off screen after being pushblocked without ending with a taunt), Polimar’s kicks assist will stay out fully even when pushblocked, so you have to block each hit of it, as well as worry about the point character who gets to stack offensive mix-ups and go crazy.
This also means Polimar will go through the entire attack animation of his assist, taunt before jumping off screen, then sit in assist wait period time (~2.169 seconds as calculated in one of [media=youtube]8z66Ov1YPt4#t=1m17s[/media]).
Another point we should mention: pushblocking the assist’s attack will push away the assist, but NOT the point character.
Tekkaman’s assist auto-tracks the opponent as long as they are in the air. Also any move that forces someone to stop their forward momentum in the air in TvC is a great move.
Not to mention if the assist lands, it doesn’t extend a “ground combo”, it actually gives you a whole new air combo… if you have the right character that can launch someone and still call an assist.
Roll’s bucket seems to be more of setup type of assist than a combo extender like the assists on Kurasa’s list. If anything, just landing a hit with Roll’s bucket allows for a free, albeit altered combo which should be useful for any character in terms of mixups and the like. The bucket also hits OTG oddly enough but its range is dreadful. Of course if Roll just flat out misses creating puddles never hurts 
