Oak? Chop..

First off I think this is an oak. It’s a long growing “weed” in my yard my wife wanted gone. Little tiny oval leaves. And it’s growing under a huge live oak from the neighbors yard...so that being said I dug it up because the wife made me. Lightly trimmed the roots and threw it in a pot. It started to bud like crazy and I let it sit for a month or two, now that we’re about to start warming up in Vegas I decided to chop it because it was to big for the smaller pots I had. Should I have gone shorter? This is kinda a cluster project because of timing but hopping it’ll survive, it lived with no irrigation in Las Vegas for years so it’s def got some spunk.

I picked a old bud to cut too but kinda think I should have gone lower, or to late and Leave it? Or chop it down another couple inches? I just chopped it Saturday. FYI the pot it’s in is MOSTLY drainage rock prob 6-8inches of bonsai soil and it’s sitting on a tile, not that it needs help flatting out...

If you dug it up and then hacked the top off again only 2 months after lifting it you probably severely weakened it's chances of surviving. If it threw out loads of buds which have been removed that was it's way of regenerating which have now gone.
If it fit in the pot to start with you were better off just keeping it in that pot and making sure it was kept moist instead of reducing it's height again.
Can't help with the identification though!

Yea I realize that. I just got worried cutting the roots to fit in the pot and with it being that tall. We’ll see it’ll prob die but we’ll learning mistake lol.