Silversea is an "all-inclusive"* luxury line. No, do NOT tip your butler on arrival. I suggest you post this question on the Silversea board, but in a different format. Perhaps ask the frequent Silversea cruisers to explain what is included and what is expected of the staff. The "all-inclusive" lines do adjust the salary of the staff to compensate for gratuities that would have been paid on a mass market or premium line.
https://boards.cruisecritic.com/forum/108-silversea/
On a recent Silversea cruise we did receive "above and beyond" service in a very special circumstance and we did choose to tip. Otherwise, nope.
And, as mentioned previously, a positive review means a great deal to the individuals serving you.
*The asterisk is because nothing is totally ALL inclusive.