While I firmly believe that finding a partner (both mixed and same sex) and sticking with that partner until death do you part is the way to go.....
I will say that when I captain a ladies team (I'm a non-playing male captain)
at the 3.0 level, I usually went with this strategy and it seemed to pay off.
I-Formation, consistent hitter in the back, better net player in the front. If you have a 3.0 lady who can lob like no tomorrow, place her with a net player who is aggressive and watch the points flow easily.
I think once you establish your teams (pairs) that you do not change them until BOTH players have requested a change. My #1 men's combo doubles team went at each other like cats and dogs on the court at times, but they were simply the best compliment to each others game that we had. Therefore, they stayed together and went 8-1 on the season.
The hardest part about being a captain is making the decisions of who to play.
I would suggest that if you have a ladies 3.0 team that you do the following:
1. Define your singles players
2. Have a round robin with your singles players to determine your singles seeding (1-.....)
3. Assuming that you only have two singles players, you are in great shape.
4. If you have 2 or more, then you must determine if you make it to a state level, are you going to play a 3rd singles players?
5. If the answer is no, then I strongly suggest stating this up front and letting your #3 singles player know that they may best be fitted for another team.
6. If your answer is yes, then you need to work a rotation. I would work it to where in an 8 match season you play your #1 6 times, your #2 5 times and your #3 5 times.
In doubles, simply repeat this strategy.
Let's face it Cindy, I can tell you take your team tennis as seriously as I do in my area.
When the nuts come down to time to get crushed to go into the pie, you are the one who has to make the decisions. It's hard to tell friends that they are not going to play at the state level. That's why after the first time I went to state I changed my team policy to the "You got to beat someone to play".
You may lose a friend or two, but I think you will gain the respect of those players who are working hard to improve while on your team.
As long as you beat your rival, who cares who you lose to!!!