What happened to the Kraang blending in with the population?

[neatoman]

So the vast majority of the series presented the Kraang donning the same disguise, mostly for the comedic value of "Haha, these idiots subvert the point of disguises!". The season 2 finale however depicted some greater diversity in their disguises, most infamously including Irma in that.

Here's the question though, if the Kraang were able to do this all along, why were we only only shown their useless disguises up until that point? Considering that it was probably the last time we would see them make use of disguises to fool humans, seeing how it seems the staff has other plans for them, it came across as pointless to reveal that concept so late.

Was it some idea from Ciro's pitch the writers scrapped in favor of comedy, so he decided to squeeze it in where he could find a blank spot?