Wow, that article is quite a load of crap, trying to stir the pot with hearsay.
Where have you seen the French "speaking out like this"? The only French player who's talked about Sexton so far is Eddy Ben Arous, who vaunted his kicking game and game management and said they would target him "because he's the key player in their team"...
Now, let's get real: Sexton had maybe one great game and 3-4 good games in 2 years at Racing Metro, otherwise it was ho hum at best. Not exactly the kind of contribution you'd expect from the supposedly best NH flyhalf. The game plan might not have suited him, but as average a 10 as Benjamin Dambielle dealt with it better. The scrumhalf general argument didn't seem to bother countless 10s plying their trade in the Top 14 and organizing the game very well without their 9.
I really hope we don't use the same rubbish tactic of trying to knock out Sexton with Bastareaud crashing it, it didn't work at all in the last game, besides showing how clueless we were in attack.