Pretty interesting, but I say Nebula has a slighter edge. Mainly because she has better experience since she’s been training under Thanos and been fighting in space for a while now and done more.

I don't know about done more. The Major is prior military and has been a full conversion cyborg far longer than Nebula has been an enhanced one. Motoko is also the more skilled fighter.

So, then, I’ll say her. I don’t know her and haven’t seen her in the anime she’s from, so my knowledge will be below average in this predicament. Sorry. lol 😂

How does Nebula not just decimate her in one hit?

You've obviously never seen the Major in action. More agility, titanium endoskeleton, and routinely deals with future tanks. Unless Nebula moves faster than automatic high caliber rounds, she is going to have some difficulty. Also, the Major's thermoptic camouflage commonly confounds future sensors and she is known for hacking cyborgs.

Did you look at the pages you linked though? The major wouldn’t even be able to hurt Nebula if she just stood still and took the hits.

The highest attributes for Nebula are with the Infinity Gauntlet, she doesn't have it for this battle.

Reading is fundamental.