gemy,
HA HA, that sounds like my two as well !
My Male Sneakers is a LOT more aggressive than is My Female Becca.
I always Crate them together, just to make sure that She doesn't get
in one of her more friendly moods, and not have some backup.
Locking their crate is a good idea, but...
I've always had a small/short piece of Chain available,
There are numerous post/other "attachments" which would
keep the Crate where you put it !
When not in use, I just pitch both chain and lock underneath
the Pad, and they're there when you need them.