I once took a group lesson I loved where a the teacher intentionally picked out three beginner things that "start" the same and discussed what the leader needed to do so that the follow knew which to do. So, sort of like "AB" vs "AC" vs AD. It made it clear to leaders that merely indicating "A" didn't fully and completely reveal what pattern it is to the follow. You actually need to continue leading!
I had a teacher who did that as well! She called your elements B, C, and D "high-contrast leads," because they all look the same at A and then branch off. The objective was less learning A, B, C, and D, and more learning that they can be sorted into almost any order ("almost" because not all combos make physical sense), so you should never, ever assume that one order is standard.
I had a different teacher whose thing was "three ways in, three dynamics in execution, three ways out." So, when he taught, say, B as the day's goal, he insisted that each student couple find their own A1, A2, and A3 to put before it, their own B1, B2, and B3 as variations on it, and their own C1, C2, and C3 to put after it. When he had few students and a bad mood, he made us dance all 27 possibilities {A1, A2, A3}{B1, B2, B3}{C1, C2, C3} in front of him, and until we could dance each one fluidly, he wouldn't acknowledge that we understood B.
This second teacher was the same one who disliked people assuming that turns would be front-side-back-side in a slow-slow-quick-quick-slow timing, or always continue in one sense. So, he made us dance turns that were all front or back steps, or front-side or back-side transitions, in every timing from all slow to all quick, with direction changes as he called them out on any step. However you feel about that artistically or pedagogically, it taught leaders to lead their turns and followers not to fall into default stepping. To this day, when I vals with followers he taught, the level of expression is much higher.
I rarely run across leaders who are clear but over control. Overcontrol is generally forcing position which, in my view, is not "leading". Good leading primarily indicates. It can also help. But it never forces a move.
We get those in tango, but also leaders who don't force anything yet leave no space for interpretation. For example, every simple step can be tripled (or, if you're fast enough, quintupled, etc.) without ending up in the wrong walking system, or the follower can insert a pause in many places. However, there are leaders who – more with their glare, sudden tense body language, refusal to invite again, etc. – make it clear that such things Aren't Done. So, they are controlling even if they aren't physically forceful.
I don't see proposal counter proposal as different from lead-follow. I thought that's precisely what lead follow is.
A certain kind of tango traditionalist really, truly believes that leaders must be manly men, followers must be womanly women, and Mr. Macho is In Control of the Dance. Follower counterproposals are unwelcome under pain of possibly being criticized on the spot, certainly never being invited again, and conceivably being gossiped about as a bad follower. Mr. Macho gives orders, not proposals. It's still lead-follow, but in the sense of boss-employee, not spontaneous negotiation between equal partners.