Sauron's Super Army?

[Zigûr]

Originally Posted by Inziladun

I wonder if the maximum number of ring-slaves was not connected to the fact that even Sauron must have a limit to his power.

I think this seems likely. When we hear about, for instance, the Lord of the Nazgûl being stronger during the War of the Ring due to being invested with "added demonic force" (Letter 210) it would seem likely to me that Sauron could only perform feats like this within a limited pool of power. Like Morgoth that power could not simply arise ex nihilo. Morgoth spent his strength on invigorating his servants repeatedly, with dragons, balrogs and so on. Beyond controlling his armies, Sauron's much lesser strength seems to have been confined to things like invigorating his most powerful servant. Presumably there would be, in the same way, a limit on the number of wraiths he could control, with or without the One.