I'd have an easier time following if you gave some examples of the traits you're specifically hinting at.
Lets take Ivysaur and Wolf as two examples here, as I feel they actually have a bit in common and I don't feel like picking on some other chars at the moment and are generally seen as two of the better/best characters in 2.6.
Both characters have an incredibly powerful diagonal kill tool that requires proper positioning of the foe to hit right, as well as a safe means of getting the foes diagonally airborne to begin positioning. Ivysaur has Back Air which not only hits foes into the air and to the side (perfect for a plethora of other moves) but also hits twice and covers a huge area, making it a reliable way to control momentum as it keeps foes at bay on top of potentially starting an offensive. She also has Razor leaf to control space for a good deal of time, which leads to either a Bair or Grab, the latter of which can lead to an easy diagonal kill if she has Solar Beam or a Vine Whip (harder to actually hit, but doesn't require the charge-up). Similarly, Wolf has his Shine that sends foes up at a diagonal which he can send out once he gets in, which is not too hard of a task given his blaster which covers a lot of space for a lengthy amount of time combined with his impressive speed, which leads into his aerial game for Fair or Side B finishes.
On the flip side, a character like say DDD has an amazing grab game, but everything else feels disjointed aside from throw offstage -> try to gimp. Everything else doesn't seem to mesh as well as say, Wolf's gameplan which not only feeds into itself, but has incredible reward for doing so. A similar example could be Falco where his gameplan is to for the most part deal out vertical combos that convert into a vertical kill (Spike), which is supplemented by his ability to again control space to get in with the moves that send foes into that key spot (above him) in order to begin a pillar and dictate momentum for a time, which then leads to his ability to finish the foe off. Like Wolf, his gameplan feeds into itself but then he even has a bit more options still using the original playstyle (thanks in part to huge amounts of time spent exploring him, but also by the nature of his moves / attributes). Again on the flipside, Squirtle has great speed going for him as well as Bubble, but it seems like he is missing something of a real "edge" like how when Ivysaur pops a foe into the diagonal space that keeps him back (along with in my opinion slightly less reward for the amount of stuff he usually ends up doing vs a foe that somebody like Ivy accomplishes by throwing a leaf and reading the reaction).
Most likely overly simplified yeah, but this is something that's been in the back of my head for a while that I though I should let out: the more your moveset feeds into a winning strategy, the more likely the character will excel.