"Hold your serve and break the weaker opponent's serve" is no strategy.
It's just a goal. And that goal may be harder than aiming to "Hold your serve and break the stronger opponent's serve." For, when the weaker player is serving, the stronger one is at net. He may do you more damage there than when he's serving.
Don't underestimate such teams. Those teams (comprised of players of widely differening ability) are usually surprisingly good at winning. That's because they naturally role-play.
If this team is any match for you, just hitting everything to the weaker opponent will not work. That too is no strategy: it's just a tactic. And if you use it, it's your only tactic.
Hey, are you going to "hit to the weaker player" when he is at the baseline instead of volleying through the Hole
because the stronger player (at net) may get a racket on that shot? I hope not.
In doubles, the SITUATION is usually more important than who you hit to. Which is why you play "deep to deep" and "short to short." No matter which opponent is in which spot.
True, when they are both up or back, then you can pick on the weaker player. By all means DO if that works.