You confuse canonical Old Church Slavic with Slavic in
general. The source of these Romanian words had syllabic [r.]
_not_ [rU]. See? <trn, trg> etc. The most common substitute
for sylabic liquids in a language that hasn't got them is
[Vr], with a central vowel if possible. The same happened to
syllabic [l.], as in tâlmaci 'translator' < *tlmac^I or stâlp
'post' < *stlpU.
this one is one of the best explanation for me regarding the
"r." & "l."
How I said, there is for me a lot to learn about .. mrr, and
from OCS and slavic and proto slavic and common slavic to,en
fine, the actual slavic languages.. a way with a lot of