Zero. Because I'm not the biggest or the baddest, but I'm always the meanest and much better trained.
ETA: I sincerely think you're overestimating the value of your training, and underestimating the value of your size and inherent strength.
When I'm the dummy (which I always am in the courses), I don't just stand there. I resist, and realistically, so they learn what works and what doesn't.
Eta: I wear a cup and depending on what we are working on, specific protective padding. I don't wear chest or abdominal protection at all, and I let them hit me. You can swing a freaking baseball bat on a guys torso and he'll barely flinch, because it is a strong area. You need to target the weak spots that even guys don't think about protecting much
Look, I get where you're coming from - you want to encourage these females to fight for themselves, to learn how to defend themselves as much as they can. I'm all for it... although I'm rather more inclined to concealed carry than fisticuffs. I appreciate your intent, and I 100% support female self-defense classes.
But if you instill a sense of false confidence, you're doing them a disservice. It sucks, I can't express how much it sucks. Like, in a completely irrational way, I don't even like putting it into words - every time I type this out, I flinch, because I absolutely hate that it's true, and it borders on superstition how much I don't want to speak it into the universe.
But to actually *be* safe out in the world, your students need to know their limitations. Not hypothetical wishful one, but actual real limits. They need to know that size and strength are real and extremely meaningful.
If you think you're 'too trained' to be a realistic example, ask some of your untrained male friends to take part. Seriously - all they have to do is pin the females down; all the females have to do is get away. And if you're worried that your female students would hold back because they don't want to hurt your male friend... keep them pinned until the fear sets in. It's a horrible thing, it will feel like a horrible thing to you and to them, and they'll be absolutely pissed off about it. But I genuinely believe that it's in their best interests to actually be pushed to their absolute limit, to be confronted by someone who is NOT playing nice and looking out for them, to be faced with the reality of male physicality and strength.
I get the feeling you think I'm cavalier about this - I'm not. I'm not a particularly physical person, and I have absolutely dog-◊◊◊◊ coordination. But I will fight with every ounce of my being if I have to. But I know, I mean I really truly know what I can't do, and that leads me to be aware of my surroundings and avoid being in situations where I'm that disadvantaged. It's not fair, it's not nice... but it's rock solid risk mitigation.