That depends on what you would consider tough.
At this level Bard, Genie and Bro buffs are the hardest titan buffs for us (despite Frost who must always be killed last). Because all other damage buffs like from Aqua, Dragon Lady etc. won't have a chance to hit once you freeze the screen with skill animations.
Regarding the minions all backliners (incl. Squirrels) are harmless. Deers, Golems, Terror Eyes and Frontline Archers can hurt you badly.
So using that definition: Yes we get hard Minions and Titans. Bard appears often, we had Frost and Bro combination at level 665, we had a deer and golem combination at level 650 etc.