Your right to say that MX has changed in recent years but don’t be drawn into the notion that if it works for the top players it can work at any level.
Watching decent quality league MX last year I have to say that, unless the lady was really strong, the traditional formation had the edge.
I can sympathize with your frustrations but hoping it will resolve on it’s own is not an option.

Doubles is a team game and, as such, requires a good degree of communication. This is when the difficulty comes.

No one wants to be criticized by their playing partners and doing so can open a can of worms.
So what to do.
You BOTH need to look at your game individually and collectively and have a discussion.
Don’t do this on a match night.
A good idea would be to book a court and tell her that you need her help on a couple of aspects of your game to make the partnership stronger.
Start by asking her advise on how you can improve a weakness in your game. Go on be brave.
Once you have a dialog going try a “praise burger”. Praise then the point finishing with praise.
It could go something like ” Your short serve return is really good but when your flicked and I’m stuck at the net I feel vulnerable. Your net play is a lot better and I’m stronger at the back, is there anything we can do to get you into the net quicker.

Hope this helps
Roger

In my league I’ve seen quite a few ladies almost playing level doubles in a mixed partnership. Quite a few don’t really like mixed and prefer ladies doubles, and on club nights they want the man to serve at the T as in level. This is okay if the lady a/ has reasonably good mobility, and b/ can play effective shots. Unfortunately in my experience neither a or b has been the case and these sort of partnerships are easily found out and exploited by opponents. I don’t know…maybe it’s some sort of feminist thing?!