>>119289284>Pinky and the Brain can defeat Danger Mouse no problem, but could they defeat Crumhorn?
PatB level of haxx or crazy shit they can do varies by short. Now it's "canon" to the reboot that Brain invented the internet, smartphones, and basically the entire modern world and he's invented time travel and mind control that controls everything on earth at once and I think death rays and shit. It's probably an Invader Zim situation where they can't take over the world because of the obvious, but if they were saving the world instead they'd wreck shit and stomp. I think that happened in some Snowball episodes.
As for taking out Danger Mouse, typically they'd need a compelling reason to want to do so, Brain doesn't (or didn't used to) target people without a good reason. If Crumhorn could trick him into it as part of a take over the world plot, sure.
As for a team up, it's been a while, but I remember Brain not trusting anybody but Pinky or his own creations. That's why although he was in love with Billie he tried to beat her to world domination instead of even considering a team up. If he knowingly teamed up with Crumhorn, he'd expect to get stabbed in the back and have a contingency, although it might be a shitty contingency. When they get serious like Danger Mouse with Penfold, Pinky is Brain's Achilles' heel.