It depends on the teacher(s). We've had private lessons individually, but mostly together, with male leaders and female followers as their primary role, and couples - with their primary role and swapping. You sometimes get another perspective from the other sex in the alternative role. For example we (me first) learnt volcadas from a male 'leader' with him in the follower role. He's taller than me and put all his weight on me. I suppose the main justification was 'safety'. If I could support him (extremely simplistic viewpoint!), then we were 'safe' together and with others.For private lessons, if I am a leader, is it better to go to Leader(male) instructor or follower instructor. I mean all instructors learn both roles for teaching purposes, but when they dance at milongas or practicas, they usually dance in their main role. So, should leaders go to leaders?
We (me included) also had privates with a female primarily follower. Learnt a lot of basic leader technique there.
We've also had private lessons with other couples where one has observed and given their perspective - almost always extremely helpful (including the occasional domestic disagreement - he got his lead wrong accidentally, so she demonstrated what should happen with him following! Great argument in Spanish!).
I guess it depends on your teacher. There are no qualifications for an 'instructor' (except, maybe, in ballroom)! A primary follower/leader may just be keeping one lesson ahead in their alternative leader/follower role. And especially your 'level' (let's say beginner, novice, intermediate, advanced) affects what you get from them. A follower may not fully understand the lead; a leader may not fully understand following. And there are always the subtleties of leading/following some move.
It's not just about lessons. It's the practice time with a partner, and different partners of differing standards. I wake up with my dance partner and we've been sharing our perspective with each other for decades. I can ask what I need to do to lead some move better - it's not just 'steps'. I can explain what I'm trying to do - and she can tell me that's not working. But you also need that practica to talk to other leaders/followers and get feedback.
The best option is to try it and see! But be prepared to move on. None of this is likely to give you musicality to interpret the music to steps. That's up to you to listen, and become familiar with, AT music - and then try it. Instructors can usually give you some basic clues.