Making a race's xp rate drop if you pick an "invalid" combo is like a double
whammy. Picking an elf nomad will naturally lower xp rate as elf is not
geared toward nomad guilds. So having it lower even mre would then make
choosing other than "standard" nomad races NEVER happen.

Ah... i misread Blayke's post... ignore my last post...

But to grant a bonus to non-fitting guild/race combos makes no sense. Why not
just make all races the same statwise and different in name only... It makes
sense to me that cyclops and giants will be best raw/physical strength
characters and would naturally make good fighters... Unless you even out all
races and make them the same, there will always be a best choice race for a
guild, at least the way current guilds are coded. An all or nothing straight
line of advancement has no specialization.
Merchants do a decent job of specialiaztion and thus can have different races
max out only certain aspects of guild (humans for spell services/dwarves for
mining), but most guilds are dry and straightforward, yielding nothing to
multi-racial specialization...