Aggressive axolotls?

I have three axolotls and they like playing with the turkey baster.
My problem is that lately, they'll snap at everything. I've noticed them snapping every time something happens to disturb the surface of the water. My oldest, Bubbles, isn't quite as bad, but my near-adult, Midna, is, as well as the juvenile, Seren. They will attack that turkey baster if it is in the water. I'm wondering if this aggression will be redirected to one another when I introduce them as tank mates.
I plan on getting a large tank, probably around 75+ US gallons. Something else to note, I often stick my hand in the tanks. Bubbles and Midna often crawl on my hand, sometimes nibbling my fingers, but Seren swims away and will have nothing to do with me unless I have food. She is very easily scared and has been known to swim erratically around the tank if startled. This can be triggered by a worm, and if she's startled, she won't eat.

Are they hungry? Mine get snappy when they are due to be fed - we've lost tail chunks, fingers and toes due to misdirected chomps.

Axies are programmed to investigate almost anthying that moves to see if it's edible - your fingers, turkey basters, plants etc, and I have found the best way to prevent it is to keep them well fed, and to make sure they are separate when I feed them i.e. away from the others (rather than in a separate container)

This makes sense, but Seren just ate her second whole earthworm, and is still snappy. I also feed the others once or twice a week. Maybe more of they look somewhat thin, or have produced more waste than usual.
I think they're pretty well fed. Midna is rather round, but I guess this is typical for females, and Bubbles' belly is about the size of his head.
I just feel like it would be easier to take care of one tank, and I also hope to become an axolotl grandma.

I know this goes against the advice I was given, but I have a 7" and a 8" living together that are fed every day. They never snap at each other unless I'm feeding them and they get a little carried away but I've not had an injury yet...touch wood.

They get two to three worms each daily depending on how small the worms are. I find they're always hungry for them, and, weirdly, they aren't getting fat at all either.

Maybe feeding them more will cut the snappiness down? Also, I found they were actually LESS snappy when I put them together, which I know doesn't make sense, but it's almost like they didn't want to accidentally hurt each other. Just don't leave it too long to introduce them as they will need a little time to get used to each other - mine were 5 and 6 inches when I introduced them, and we had no problems apart from them getting used to each other. Hope this is helpful!

I've actually had them refuse food though. They sniff it, and walk away.
They even snap shortly after eating.
I just want to know if it's something I need to watch out for.
I once had my older two in a separated 45 US gallon, and when I actually separated them, they started hang out at the joining side all the time. I think they miss one another.

I think it's one of those 'suck it and see' things. You won't know for sure unless you put them together and let them get used to each other - I had exactly the same fears as you. My little one, Galaxy, was mega-snappy and would bite his bubbler, his cave...anything he thought might be food. Tooth was sweet and only snapped at food, so understandably, I was scared there would be a conflict of personality.

I put them together with a separator for 3 days and then introduced them. I had a few nips but another user guided me through, telling me they were getting used to each other. Within 2 days, no nips. They have been together now for 2 months.

I'm a strong advocate that axolotls do enjoy some company, even if they seem to spend a lot of time apart. I think they like having another body in the tank and having something to lean against and lie on top of. Plus, some owners have said their axxies do pine for each other and that it's even caused some to refuse food!

I know you're worried, and I totally understand, but each pairing is different. You'll have to try it and see how it works out, I'm afraid. Good luck!