It is supposed to be funny and down right mean. Of snickering kind of humour apparently (sorry, I just fail to see the wit)
The first one I'd translate (loosely)
And this by Phocylides: The Lerians (?) are bad, (and I don't mean that) one person maybe bad, but another not, (but) all of them (are bad), apart from Proclees (sp?), and Procless is a Lerian (therefore by default, apparently, bad)
Same goes for the next one
All the Cilicians (sp?) are bad, Kinyres (sp?) is the only good one among them, but then he's Cilician so there you go.
Same goes for the English one. If you search google books you'll find (at least) one book where the author (can't remember who) explains that Germans just aren't good scholars with the exception of Hermann and another. After mildly chiding Porson for his little piece of wit, the author goes on to say that Hermann did not in fact lack anything to be considered a true scholar (being very close to the English as opposed to the German school of though or something) apart from an English education
(need to go to sleep so memory is worse than usual)