There seems to be a theory that
Ruslan was derived from the Tatar/Turkic name Arslan, which means "lion". See e.g. here:
http://en.wikipedia.org/wiki/User:Untifler/Tatar_name
I tried to find a link between
Ruslan and Ruswan, but nothing turned up. The similarity may be pure coincidence, without a common origin of those two names.