There is a big difference between the man's technique and the lady's technique. A famous teacher by the name Benny Tolmeyer always said "The man dances from foot to foot and the lady dances between feet". There will be a conflict between the man and the lady if they do the same.
True, but sometimes I will send her to arrive before me, and sometimes I will send me to arrive before her. In either case, whoever comes second has to adapt to the foot position that their partner has committed to. Forward half of turn- she has to match me. Backward half, I have to match her - not perhaps to the same dramatic degree, but I still must accomodate my partner.
As the man has the right to change the timing, direction and the step at any time it would not be good for the lady to be on one foot or the other.
I would disagree that I have the right to make fundamental changes at 'any' time. Instead, I found that learning to lead well was largely about learning to recognize the opportunities when I could change something, and that once these had passed I then had to live with the results of my decision and my partner's interpretation of it. It's true that I will sometimes give up on a particular try at executing something because the pre-requisite doesn't seem to have been achieved, even when I probably could still "muscle" us through to the desired result. But instead I'd rather change to an alternate figure that is naturally suggested by where we've ended up.
The idea of specific opportunities to inflect the movement, and then having to go with the results, also ties in quite closely with the structure of the characteristic figures of the swing dances. Typically, CBM on one (decision point) produces new line of movement on three. Yes, there's some ability to fine-tune things once they are under way, and for the more skilled dancers, possibilities to entrain the movement in a more continuous change (like driving the CBM around a curve in the actual CBM step rather that taking it in the pre-existing direction). But still, as a general guideline, I find the kind of setup and then follow through structure of the characteristic figures to suggest a very sound fundamental habit of how to move.
Obviously any reserve capacity to patch up differences in foot placement is a great asset, but I prefer to aim the movements in a way that's going to minimize the need for this. It's kind of like saying, if I have a bowling bowling ball on a string, and I launch it into this swing, then if I want to stay with it I'll have to move my own body this way. Obviously my partner has a lot more skill than that, but if I send her in such a way that her center follows the path that the bowling ball would have, and am prepared to accomodate that in my body, then she's going to have an easier time of things than if I launch us with less decisive clarity of intent and expect her to make up the difference in flight.
My partner never danced routines. He would dance whatever he felt like at that movement. We would never have made it if I had been on one foot or the other.
Until quite recently, I did not compete fixed routines either, instead preferring a dance that evolved more naturally, one figure connected to another in the moment rather than on paper. I've moved away from that to expand the variety of my repertoire, and do stick to the plan to a greater degree even if it no longer seems the best choice from the current situation, but ultimately, when quality of dance rather than competitiveness of presentation is at issue, I'd go back to the idea of committing to decisions and accepting the consequences by developing the variations that they suggest as they unfold. In short, I suggest a lot when leading, but I also do a *lot* of following in order to work with what I get.