I am a big fan of poaching and doing more at the net, and totally against "covering the alley" concept. But that being said.....
Clearly this is "unbalanced" doubles (large variation in skill level of players). And so treat it slightly different from a "balanced" doubles (similar skill level of players), especially if winning takes preference than everyone share the same number of shots attitude.
Usually on a balanced doubles the guy at the net is the aggressor and have a really high chance to finish a point than the guy at baseline, who is really trying to just stay alive (defensive) most of the time. But when the guy at baseline is a lot better in skill level than the guy at net, then at some point the guy at net still becomes the weaker component, and may even bring the doubles teams overall level down by not allowing the better skilled player to finish the points. This is when you want to clearly define, how much is too much.
Sometimes all you may need to do is just be a presense (and just not allow the opponent to attack you). This is done by pushing the weaker partner more closer to net and more away from middle (which is were most of the things are happening). But at the same time, the weaker partner still has a job to clean up anything which is directed at him. The damage you can do is intercept a neutral cross court rally and try to do a tough volley only to give a sitter and a different angle to hit to for the opponent.
In summary, in 90% of the cases, a net man should always get the opponents feel his presense at net. But there are times when not making your presense feel at net works for the team. If you don't enjoy playing as a team, you probably should not. Unbalanced doubles is not for everyone.
When a 5.0 is teamed with a 3.0, the average level of the team is 4.0.
When the partners "understand" their skill and their job, the level of this team is 4.5 (higher than 4.0 .. but never higher than 5.0).
When the partners does not understand their skill and their job, the level of this team is 3.5 (lower than 4.0 ....but never lower than 3.0).
So a lower level player could always feel like he is playing better in unbalanced doubles, and a higher level player could always feel like his is playing worse.
But if your team is feeling 3.5ish... when it could have been 4.5ish .... then it is still not making full use of the resources available.
the opponent is going to look for a way out of the cross court rally by going at me
its tough to go DTL off my partner's strong shots.