How is it decided what classes are in or out of a particular book ?

[Phasics]

For example

Ultimate Combat
No Oracle stuff
No Sorcerer stuff

but there is Cleric Stuff and Wizard Stuff

any particular reason ? I mean there are Battle Oracles and Sorcerer are probably more well know for being turn into more combat oriented characters than wizards.

Thoughts
(apart from page space)

[TriOmegaZero]

Might be that no one wrote anything for the class, or at least nothing that was polished enough to publish. They also may just not have had anyone to write up those specific options, with each author already having full workloads.

[Jeraa]

You can't assume people have splat books, so expanding on something found in another splat book (like the oracle) isn't a good bet. People won't pay for material that they can't use. If, however, you expand on the core rulebook (Something that is safe to assume everyone has), then you know your product will appeal to the widest possible range of players. At least, that seemed to be WotC's stance on the subject. Paizo may be different - I don't buy Pathfinder products, as I don't really play Pathfinder, so I don't know what they contain. I just use some of the core rules in a modified 3.5 ruleset.

[Immortalis]

Not adding things from splat books isnt an issue as Ultimate Combat has Archetypes for the Alchemist, Cavalier, Inquistor and the Magus in it. I think its just a matter of material they have that is up to standard and fits the book.

[Phasics]

Kinda realized a combat oriented sorcerer maybe with some funky poly morphing could have been a perfect fit for UC, meh oh well