They shouldn't be as I'm the only person using them.
As mentioned above, the /replsend.txt for the profile is using up ~60% CPU on #1 (others are 7% and 2x 3%). "monitor/Check index" is taking up about 30% CPU time on #2. The rest of the processes are trivial for #2.
One item suggested by support was to set verbosity to é (if it is set higher) but that did not help that much.
The indexing itself was not that slow in our place, but once you have several 10000 items in your replication queue it empties very slowly (several weeks for 200 000 items).
I have noticed that if a site is 'clean' (ie no errors) the replication queue tends to stay small. But if there are a lot of errors the queue size explodes.