Is it possible to change the architect?

We saved money here.

Yes, because in fact you have just not commissioned any external construction supervision. So you were simply lucky.

Phases 1-4 being done by an architect and then handed over to a general contractor is quite common. The contractor then naturally takes over the execution planning (priced in) and phases 6-9 are omitted or remain the responsibility of the client.

Yes, because by doing so you have effectively not commissioned any external construction supervision. So you were simply lucky

And time.