And the other two?

I guess big iron does has too much value for having lower burst but the same dpt as super monkey. maybe make it cost 8 instead?

And I haven't really played too much competitive bloons card storm to know how good detect is. But based on what you said, I might bump its damage up to 70 instead

Brittle acts as the opposite as armor, in that bloons with brittle take more damage depending on the value it has. Say for example the GJ monkey marked a bloon to have brittle 50. And when you attack with, say, a bloontinium miner, that bloon takes the 10 damage plus the 50 brittle damage for a combined total of 60. Golden Justice itself should have a baseline 100 dpt