Different sized axolotls together?

I live in Australia, melbourne and cannot find adult axolotls anywhere. I got my last axolotl about a year ago and he is full grown, three years old. I got him when he was 2 from my cousin. It was the last time, anywhere that ive known to sell adult axolotls. Now the place we got him from only sells juveniles which are to small to be with my one
I really want another Axolotl, have been searching for over 5 months and cant find one anywhere. I have a 4ft long tank with lots of hiding places and was wondering if I could place different sized axolotls together (smaller, non canabalistic albino axolotl with my current one)
I just went to a pet store that claimed to sell adult axolotls that were roughly 25cm plus but they were actually babies that barely fit 15cm in length with shrunken gills. Pathetic.
I have found in the rare occasion, an axolotl between 15 and 20cm (I pressume) but was unsure. They are housed together with no signs of damage and are very peaceful with eachother.
If I were to get a smaller one, would it be able to live with my adult? I havent been able to measure him properly but last time he was 25cm and has gotten fatter with larger gills. He is black and has been housed with other axolotls before.

At 15cm, it should be just fine in an adult tank. I've had adults that were less than 15 cm.

What you don't want to do is put a 8cm axolotl in with your 25cm one. It'd be a snack for sure.

One of my axies is around 26cm and is housed with another that's around 19-20cm. The size difference isn't great but they are fine together. She is a rather large monster and he is the tiny cute golden you see in my avatar. They even had babies!

Oh thats awesome! I would never put a little baby like that in with him though!
could somone show me some pictures, of your axies and there size differences? that would make me immensely happy

here are mine, the female golden is about 19-20 cm and the male wild type is 14-15, they've been fine so far... living together for a week or so ...