Why were House Crakehall’s forces involved in the Kingswood campaign? Surely lords of northern stormlands or the southern Crownlands were situated much closer & could mobilise faster?

The most logical explanation would be that Sumner Crakehall was part of Tywin’s retinue at the Red Keep, or was in the capitol for a tourney, or something like that. 

Think Beric Dondarrion in AGOT.