In a typical organometallic cross-coupling, bromo-pyridines perform faster oxidative addition. Yamamoto coupling might be different though as I think it's a radical initiated reaction, not a "standard" oxido-reduction catalytic cycle, so it might no be compatible with 2-bromopyridine. You want to make dimers? If so, I try an Ullmann coupling first. If not, I would use a different coupling, like a Suzuki or Stille. For those, chloro-pyridine is reactive enough to react readily less reactive catalysts like Pd(PPh3)4.

I agree with Pierre.

N atom on the 2-bromopyridine make the compound more towards Yamamoto coupling reactions compared to regular bromo benzene