I don't know if it is a problem per-se, however if you capture a noble
and decide to execute them. The obvious first action to do next is
to perform last rites, so they can't ressurect them.
In the playtest I had a character who was killed twice by enemies, and
not last rited(?) he was quickly ressurected and the death was just
4 or 5 weeks of lost time, no inconvienence.
If you want it to be difficult to permamently eliminate high-skilled
characters (those worth the effort) make it so that you require the
body and/or are a memeber of the person`s faction to perform last