"Default" constraints?

Hii there,

I’m looking into adding a three nodes into my swarm (one tiny guy as the “manager”, one big powerhouse as a “worker”, one for storage, the existing node - yes, 1 node - will become a “worker” too) but during my experimentation with it, I noticed that my test containers would be fairly randomly spread between my “manager”, my “worker” and my “storage” nodes.
This is, of course, because I had no constraints added to my stack.

So I wondered whether it would be possible to have services that have no constraints specified to deploy to only my “worker” nodes.
Normally, I would add the worker constraint to it but let’s say I forget to do this, is there a way it automatically just deploys to just my worker nodes or?

Thanks in advance!

(ps. sorry if this sounds like a stupid question)