SCs for Mega Menu fails

When a site has a large and distracting Mega Menu that is often 
triggered accidently on a mouse over, for example,
I think this should be a flagged as an issue for many users. The 
question is, are distracting Mega Menus (DMMs ;-)) considered a fail of 
either 3.2.1 On Focus/3.2.2 On Input ?
I personally don't think it's either but, I need a way of saying to a 
client - 'This thing is disorientating and will be confusing
for some PWDs, and regular users will thank you for removing it'  but if 
I can't call it out as a fail
of a pertinent SC - then my advice will likely be ignored.

So I'm wondering if (in the future) we need a new SC or change an 
existing one, to cover user input/interaction error?
Or do you guys think 3.2.1 On Focus/3.2.2 On Input are sufficient (with 
a small s).

Thanks

Josh