Perhaps. But (reading through the source books) he was playing a character who tries to maintain a distance and an objective view of a case. Now Kitchen, in Foyle, played a character who tried to maintain a calm, thoughtful outlook. Even on the rare occasions he lost his temper, it was very controlled and bloody obvious, but more an impact for all that.
Oh, and humour?
In Foyle, first episode, he's assigned his female driver Sam and tells her to stay in the car. Chase with criminal takes place and it looks like Foyle's losing him ... until he get's decked by "running into" a dustbin lid! Sam just smiles, dropping the lid.
For content balance, I'm all for crude humour and obvious pratfalls (vide Bottom, The Young Ones, Fr. Ted etc.) but Mrs Brown's Boys are beyond me. Strikes me as they're trying to be funny by being rude, rather than while they do so. Even Men Behaving Badly did this better.
Oh, and Ricky Gervais? Might be a clever bloke, in written form, but he always appears to me to be insufferably smug! Even in Upstart Crow, he's gently parodied as being thus!