"Anonymous. I think we have two things here. We are thinking more towards dancing with a strange person who has no idea what we are going to do. So we use the strong arm stuff."
No. No strong on arm, just clear leading and a skilled partner.
Easily demonstrated by leading a skilled dancer (such as a teacher) through your routine which they don't know. If it doesn't work with a light ordinary connection, you aren't doing your part right as the leader. Chances are it will work better than it did with your partner, as the teacher is fundamentally a better and more responsive dancer.
"This in a competition would be worse than useless. In a competition the lady would know immediately if there has been a change in plan."
It doesn't matter if there's a change in plan or not, skilled dancers will not go charging into something just because it was part of the proposed plan, instead they will respond to what is actually happening.
"Other than that she who is going forward should take control without being over asserted"
No, she must not do ANYTHING without paying attention to her partner. Nor can he do anything with considering if it's compatible with the actual position which she has currently gotten into.
Only a robot blindly follows the program.