I did ask Nairo why he picked Doc in the Doc Social and he did respond (for those wondering it's in the Doc social on the boards here, thx
@Nairo . He said it was cause he was a lot more used to Doc's strings and combo game (he plays Doc more than Mario on his stream cause he finds him fun I guess) so ultimately Doc was a familiarity pick as far as that goes, he went on to explain that he think both Doc and Mario do well against Pikachu (Mario prolly does better but that's not the crux of the discussion) and said that outside of gimps, the MU is pretty good for Doc cause Pika has to come in close to be most effective and that's where Doc wants...well, anyone.
So it was actually a thought-out counterpick based on what I will consider to be like, experience and time invested. I do think it's relevant to discuss characters like Doc having good or decent MUs with relevant characters, whether they are high tier or even top tier, because it's MU discussion which is in it of itself fairly healthy, but also because it can substantiate interesting insight into the idea of counterpicks and the role of said character in the game.
I think it's pretty easy to say that this established Doc's role as a secondary/counterpick type of character, but more insight and discussion into other MUs that AREN'T just Pika would also be great. The only other ones I can think of where Doc functions well (well being like, not horrible. By no means largely advantaged) against high/top tiers are
- Mario
- Luigi (yes really)
- Fox
- Ness
I just don't know if we have ENOUGH data to talk about these yet. These are just MUs I can safely assume/suspect to be reasonably doable and not disadvantaged enough to be notable. We've talked about his crap MUs more than enough I think (ZSS is summed up in two words: Flip. Jump.) so if it's even worth going on about, these are the ones I can think of as far as competitively relevant and frequently occurring characters. I've had thoughts on Doc vs. Falcon being okay-ish (he loses by a bit I think, personally) because their punish games on each other are Grade A disgusting tier and Doc can discourage a lot of general Falcon decisions if he plays smart.
I think with all this in mind, approaching Doc as "defensive Mario" is probably not the best mindset at any rate. I think he trades off Mario's ease of getting in with an advantage state that ranges from a bit lackluster to much more depending on the fall speed and weight of his opponent (D-Throw > Fair working consistently on some strong competitive chars for instance, alongside a lot of Doc's combos and strings being stronger against certain weights), I can't think of any place Doc wants to be outside of up close in some way. (On that note I REALLY want those MLG VODs to get uploaded so I can look at the strings used in the LF set again just to see optimal strings and dmg vs. perfect character weight)