I suspect playing a non-Oathbreaker Paladin until the Enhanced Edition will mean keeping 2000gp in your pocket at all times for this. Talk about pay to play! (Or a lot of quicksave/quickload I guess lol).
Right now, you get broken oaths really easily for absolute nonsense due to how lazily flagged the game is - loads of hostile NPCs are flagged as innocents, including the goblin who is actively torturing a gnome (!!!) - and Ancients Paladins seem to be held, bizarrely, to Devotion Paladin standards. It's particularly enraging when you get attacked, defend yourself, and then get "oathbreaker". It's also inconsistent, because it seems like it's maybe killing-blow-based, like if you last-hit a goblin that's mis-flagged (as some are), you get it, but if another party member does the last hit, you don't, even though the outcome is the same.
It really sounds like Oathbreaker will be the only sane choice at this point. Given how Larian haven't acknowledged this issue, and their history with bugs in DOS1/2, I would guess this will stay with us for a very, very long time lol. I was intending to play a Paladin first run but I suspect not unless Larian acknowledge this and promise to fix it.
Kudos on locating the exact first moment in the game where you can be an Oathbreaker lol. Those poor Tieflings are seeing a lot of angry people with hammers right now!
Control Undead is a spell that lets you summon an undead rather than, er, controlling undead I note, in BG3.