You said this-
'to my knowledge there are no full-size submarines that work on jet propulsion. So if you're in the accuracy camp you'll not find a model jet submarine'
I gave some examples of what I consider to be jet, or thruster propelled boats in model and fullsize form.
Your design still uses impellers to provide thrust- they just happen to be hidden away inside the bilge pumps.
Therefore, the subject you have chosen to model with jet propulsion is unusual, but the idea of jet propulsion on a model sub is not so new.