Doncic archetype is scoring guard/shooting guard 3 level scorer first and PG second. Its what he was in Madrid, and when he played with Dragic for Slovenia.
But for NBA he is defenitely the PG for Mavs, not just primary ball handler but primary playmaker, his style is similar to Harden, but he is even more of a playmaker then peak Harden.
Nothing wrong with calling him a PG, PGs are alot of scoring (smaller) combo or shooting guards types now. No more just CP3, Rondo or Ricky Rubio types anymore, that changed long time ago.
So in positional system Haliburton is no more of a PG then Doncic, even if Haliburton gets compared to Nash etc. Doncic can coexist with a PG as SG or SF or be the primary PG. Either works.
Shai technically plays as PG for OKC, but in paper mainly, because they moved Giddey to SG, but he does alot of floor general tasks for them. Shai is more like the lead guard for them just out there being an assassin. Does some playmaking, but he doesnt build up for others like Doncic does. Shai plays more like Kobe sometimes lol.
I would disagree Haliburton is the best PG, IMO he quickly gotten overrated despite doing fine with magnificient jump as a player. He is the IT breakout player, but he needs to do alot more to be compared to the Doncics, Currys or even Fox of the world etc. Need to do it over full season etc.