Is it deliberate that the little mini-boss fight at the end of Assault on Machine Shop 13 seems to pick a monster family at random to throw at you?

One time a while back I had Slimes for my Battlepod fight. I did not think too much of it at the time as I had a Shadow sword packed for dispatching Menders so the Jellies were no problem.

Then last night I found myself solo in Devilite hell complete with Firebrand Overtimers, Pit Bosses, and Yesmen. I was not even close to equiped properly to handle this, because I was heating an item in the weapon slot that would normally have held my Piercing blade... I had Elemental, but the Rocket Hammer is a terrible choice for fighting devilites. They also never quite spawning.

I abandoned the mission and tried again only to find regular 'ol expected Constructs for the Battlepod fight.

I don't want to complain. I prefer things to be challenging and I'm not a big fan of the nerfs that many of the monsters have received (Wolvers, Zombies, Grievers). All I want to know is whether or not this is a glitch? For now I will operate under the assumption that anything under the artificial sun could be thrown at me in the Shop 13 battlepod fight.