Jyprez, in your situation with a SS phono section and a tube preamp, I'd say you are doing the right thing already.
The SS phono section is generally quieter than most tube phono sections when High Gain is selected, because there is no tube noise. You can use all the gain you want in the Plinius phono section. The Lamm preamp is tube, and tube input sections generally are very forgiving of any overload on the inputs. Also, the tube preamp may have some tube noise if you have to turn it up high.
So, your combination of high gain in the SS phono section and using less gain in the preamp, will likely give the least noise, and low probability of overloading the inputs of the preamp. Also, amplifying the very weak phono signals earlier in the chain typically gives less losses from lines, and connections, that can cause the very weak phono signals to lose low-level information before they get to the amplification stages.