In my opinion, the individual award should always be done by the architect who also made the plan (and who also supervises the construction)!
We can obtain quotes ourselves.
Since we have little knowledge of the subject matter
That doesn’t add up: with little knowledge of the subject, you pay more lessons learned when obtaining quotes than you would have paid the architect in fees.
We have submitted a building application, the architect made the drawing.
If the architect only made the submission plans for the permit, further involvement will bring little benefit. Building with an architect only really pays off when you also have him make detailed plans (and supervise the construction).
A general contractor mostly has something “off the shelf” and will probably not go along with these plans.
No, they are regularly grateful for approved plans that don’t cause them any more work.
Depending on the wall construction, the general contractors have different wall thicknesses
With a finished approved planning, you have to find the GC suitable for the approved walls. How (total thickness, monolithic or multi-layer or ETICS) are they planned?
We tend to look for a general contractor who will create it for us.
Please don’t have the naive idea that a GC builds the whole house with its own staff. Some are even quasi mailbox companies with only subcontractors except for the construction manager.