Adding new scorps to tank?

Hi I just upgraded my tank from a 10 gal to a 20 gal. added another couple inches of substrate (now 5-6 inches). My question is if I add new scorpions to this tank would I need to quarantine them before I put them in? I know I should make sure they are all the same size to keep them from eating each other. I am hoping to get a couple more at most and at least a female. (I am 99% sure the two I have are males)
Would a 20 gal be large enough for 3-4 emperors when they become full grown?

Imo, yes, 20 gal would suffice for 4 emps. A general guideline would be 3-5 gallon per specimen. A re-arrangement of the tank's deco would help to reduce the chance of territorial conflicts when you introduce the new ones in.

Quarantine wise, i do not do that to newly bought scorpions.
The only time i do it was probably due to a detection of mites on the scorpion itself and i did it before i shift the scorpion to the newly setup tank.

Be careful of fights breaking out. Some emps just don't like others. I agree with the rearangment. Make it a new enviroment for all to lessin the chance of fighting

thanks, I had read that about the rearranging of the hides to avoid conflicts.
I lucked out with my two emps, they get along great and always share their burrow. hopefully ill still have the same luck with any new ones

Good to hear.