Thanksgiving Axolotls

I went to visit family this weekend and found out a local tropical fish store sold axies. I decided t check it out, buy a pair. When I got there the store was pretty warm, when I asked they said they keep the room at 76F so they do not have to heat most of the tanks. Finally after looking around I found them, two 5 inch axies in a 5 gallon tank, light on and no hides. They were a little skinny but their gills were almost non existent. When the the store clerk saw me looking at them she said they had two more in back they got from a woman who was relocating. In the backroom it was a little cooler and they had a 10 gallon with no hides but at least no light with two more axies. These ones were had nice gills but were 6.5-7.5inches so I figured they were young, nope 2 years old. I guess the woman had had 8 axies in a 55 gallon and had sold all but these two so gave them to the petstore. The owner was in back said he would take $35 for this pair (one has a broken tail) and then $15 each for the younger ones. I decided to buy the two adults and was looking at the other two smaller ones, he said they are 9-10 months old, he watched me and said he would take $50 for everyone so I just decided to take them all. At least the tank bottoms were all bare no sand or gravel. The adult female with the broken tail laid eggs in her tub I had her in (I started a different thread with questions about that). Everyone ate some worms I feed them yesterday and today as well. I will add pictures soon.

I am just curious are the two adults who are 6.5-7.5 inches as small as I think? Might they given the space and good food (they were only fed pellets before) grow more or has an insufficient diet and over crowding stunted them for the rest of their lives?