I've noticed in several of my Normal and Hard solo games that the AI tends to make peace treaties with each other and attack me together, pirates included. Or at least, it appears that they've made peace treaties with each other because they're all sending their massive fleets at me.  It's hard because it splits my forces trying to eliminate one enemy from my star system + pirates, while defending against the other two enemies from another star system as they keep sending fleets my way.

I know for future games that I'll just lock the teams so it won't happen again.  Has this happened to anyone as well?

And also what makes it harder is that when I've got a large, quality fleet to attack, they all just run away, but that's a whole other issue.