Timburr can be caught in Relic Passage, and Gurdurr can be caught in the Passage as well as Twist Mountain.
Caught as a Drilbur or as an Excadrill in swirling dust in most caves.
Caught in Desert Resort/ Route 4 as a Sandile
Given to you on Route 6 Weather institute (as a Deerling w/ Hidden Ability) or caught on Route 6 in general
Route 23, Dragonspiral Tower or Route 14 & Victory Road as a Mienfoo
Caught as Axew in Mistralton Cave
Swords of Justice Trio
Caught on their respective routes: Terrakion Route 22, Cobalion Route 13, Virizion Route 11