User blog comment:Diyartifact/Shepard's adversaries/@comment-3228423-20120404115742/@comment-1388547-20120405043502

For the Praetorian on the Collector ship, I save up my Cain ammo and nuke it from extreme range. It's not enough to kill it on Insanity, but it shortens the battle considerably. (It also makes its AI glitch out a little -- it makes more use of its instant-kill smash attack for a little while afterward.) The Horizon Praetorian is actually harder for me, because I'm never able to get enough range to use the Cain without killing Shepard in the blast. I kill it with small arms instead. >:-)