Firenze in OOP

[pippin_999]

Neri:
 The dilemma you pointed is actually even worse because of JKR's use,
 or rather un-use, of Firenze in OotP. The Firenze subplot in OotP
 simply doesn't go anywhere. It's one reason out of many why OotP was
a bit disappointing, a transitional book rather than standing by
itself.
 Why put a rebellious centaur as a divination teacher at Hogwarts when
 he does not alter the plot of the book in any way, nor teaches us
 anything substantial? The only reason I can think of is as a
 preparation for Books 6 and 7. There are two possible roles that I
see Firenze playing in these books: he can help reinterpreting the
 prophecy, and he can help recruit the centaurs as allies if they can
 get over their fatalism and separationism.

Pippin:
Firenze has  a couple of functions in the OOP plot 
besides balancing out Fleur as eye candy <g>. The 
centaurs' attempt to kill him sets us up for their 
attack on Harry and Hermione. His explanations about 
prophecy don't provide Harry much of a practical 
nature but they do establish that though Trelawney is 
a fraud, divination itself, as distinguished from mere 
fortune-telling, is not. This is essential to the reader
accepting that Dumbledore and Voldemort  took the 
first prophecy seriously despite its dubious source. 

Pippin