You are correct, there isn't a simple answer.
Doubles is a very different game than singles. Different angles, positioning, shots required and strategy. So there is a certain skill set that is unique to doubles that is independent of singles. Those that choose to play primarily doubles focus their training and practice tailored to doubles specific tennis.
There is also the factor of familiarity and teamwork in doubles. It is a tremendous advantage to know the tendencies and position of your partner in terms of which player will take which shots and consequently how to react and position yourself.
Almost always the people who primarily play singles and play doubles on the side are more talented as tennis players in general than doubles specialists. There is 10x more money in singles along with much more fame and notoriety. Singles self selects the better players. The doubles specialists are able to significantly narrow the talent gap through doubles specific training as well as familiarity/teamwork with a regular partner.
If Federer and Nadal teamed up and practiced together for a couple of months exclusively focusing on doubles, they would beat the Bryans most of the time.
Rubin and Bogaerts basically only care about singles at this stage of their careers. They play and practice doubles primarily because they have to for college tennis. Maneouri and Seraphim likely clicked as doubles teammates some time ago. So they spend more time focusing on doubles (knowing they have no shot making a living playing professional tennis after Wake). In a way this is a huge advantage for Wake in doubles because they can put extremely talented players at 2 and 3 doubles.