I have to disagree. Capestall isnt too good of an option against Tether recovery characters; too much time to nab the edge, all you'd need is timing. You don't ever fludd when anyone's close enough to tether because at that point, it doesn't even do much. You Fludd from a distance to kill momentum, then go out for a cape/aerial to do the actual gimping. The only people difficult to gimp for mario are those that can recover above him consistently.
I don't know about ZSS' edgeguarding options, but I'm sure they can't be better that Mario's are for her.
Mario's recovery is better than his recovery in melee in every way.
ZSS is one of the best edgeguarders in the game, IMO she's 2nd only to Metaknight in that department. The thing is that hardly any ZSS mains really put that to good use. Forward B off the stage is amazing for one.
Your main advantage against us is really the cape. Right off the bat, it's going to be harder for ZSS to attack with her armor parts.
Worse than this though, and something I bet few people realize is that you can cape ZSS' down B. Because of this, Mario is one of the only characters that can truly gimp ZSS. If I'm recovering and I'm forced to down B, you can force me in the other direction and I'll most likely be screwed. So, actually this is one of the few match ups for us where the opponent will have the edgeguarding advantage. Keep in mind though that this only works if ZSS HAS to recover with down-b. Her jumps are very high and she can often even make it back to the stage without it.
In comparing recoveries, I think ZSS still has the better recovery even WITHOUT the down B.
And I'll add that another advantage for Mario is his priority. More of his attacks I believe will beat hers.
Mario's fireballs haven't really been a problem for me. Yeah ZSS' paralyzer shots are a little slower, but I can get around by just shooting one to clash with one fireball and short hop airdodge another.
On our side, ZSS has speed, range, and ability to KO in her favor. Mario may have a couple of stronger attacks than her, but they are also harder to hit with. It comes down to the fact that ZSS has more attacks that are good for KOing.
The comboing ability for both characters is very good (especially for Brawl XD). I think ZSS is slightly the better comboer though.
All in all, it's about an even match up