tools are not directly correlated to matchups because of the basics of smash as a whole makes it so that there are SOOOO many variables that some things that can be tools in some cases (like foxs fall speed making his airdodge cover a lot of verticle ground) that end up being total detriments in other cases (like foxs fall speed, when hes getting down thrown by pikachu). there are so many veriables and so many situations that can or might not be taken into account, that every thing has to be looked at on a case by case basis.
in your example, DKs large build and fatness, helps him out in a lot of matchups, snake for example, dk has the build to make him large enough to be on par with snakes spacing with his tilts, and he is in the same weight class as snake which helps even up the matchup as well.
but that same large build and fatness screws him over when he gets grabbed by DDD.
see what I mean. theres no (or very few) direct correlations between the two things you listed, only indirect correlations, that are determined on a match by match basis.