I thought the rule was same paying agent or title sponsor. So although VC Pays de Loudeac have Vital Concept prominently on their jersey if they aren't a title sponsor I think its ok. The problem would come if the were called "VC Pays de Loudeac - Vital Concept".
It says "main partner", not "title sponsor", in the UCI rules. To make matters worse, VC Pays de Loudéac isn't a UCI-registered team, but a French cycling club - who does have sponsors or main partners, but keeps its own name for the team.
If you look at the club's homepage
, they list Fortuneo-Vital Concept (the ProConti team) as one of their sponsors! So they don't have the same sponsors as
... they are actually sponsored by them!
Now, I don't really care if the teams are in a race together. I only wish there would be clear guidelines for all of this, and that they were actually applied across the board and not only in those cases where the UCI is aware of teams being run and/or funded by the same entities.