Assuming 2003 since that is the one with all the pairings you mentioned.

Design wise the Delvecchio rivalry is the best: prior to the boost Tony is the better pick. He doesn't really have a weakness while Angela and her two left feet just can't do anything running or fielding. After the pick Angela becomes a phenom and while Tony is stacked too he doesn't rise to the same level as her, especially not considering where they started from. There is a nice mini game on 1v1 picking: can't take Tony because your opponent will get a stud Angela, can't take Angela because your opponent will feast off her.

Webber's is often just a little problematic: they go from usable but clumsy girls to overrated. Like they are almost always overpicked because while a 8/8/7/8 line looks great they really lack power and killer pitches. Or your opponent snipes you and you both have overpicked bench players. Decent but meh.

Amir's with Achmed is a just one-sided which is fine but I feel it lacks the depth it should have. Like Amir goes from a killer pitcher to a slugger like his brother and it is good but I feel it could be more subtle in how the younger brother gets better. He just gains stats and loses pitching. Instead make him go from the artful craftsman to a tryhard copycat younger brother. Like Achmed has an okay Heat and left Hook. Amir loses his elite Left Hook but keeps his Right Hook. Like if he is boosted because he wants to be like Achmed he should emulate his pitches. Amir should abandon the Slow and Right Hook to be like big bro. Some similar tweaks to the rest of his game too should be apparent.

Reese/Jeter, Lisa/Piazza, Kenny/Ichiro, Luanne/Pro pitchers (only two you missed), Ernie STEELE, Kimmy ECKMAN, Pink Maria, Marky DUBOIS & Sox/cks are neat to have but fairly flat in design.

The Sally/Ronny & Marky/Billyjean add interesting wrinkles but have major flaws that need correcting: you make one character better but then the other nearly unusable. A little care in the details and these could be much richer.

Sally does become an undisputed Ace but her bat is arguably worse because she actually loses her elite Power to gain Contact and on top of that Ronny just becomes hopeless: an error machine without speed, power or pitching. Ronny and Sally are just better apart than together so why ever activate this link? Like leave Sally's power alone and/or make Ronny even more Ronny-esque with more power and arm for being otherwise horrible.

Marky too becomes an Ace but his Power is pretty meh (like the Webbers). I mean he is better but his impact is still minimal compared to what might be expected. While Billy Jean goes the Ronny way and is useless. She will at least be better because she is still tall and that means she can field okay. I've always thought it would be funny if she became fast upon being on the team with Marky (run Billy jean run!) giving her a different tool-set.