Sandile (Which goes to Krokorok then Krookodile) is a pretty decent physical ground/dark Pokemon to use. It can be caught in Desert Resort.
Similarly, in Desert Resort you can catch;
Dwebble (Evolves to Crustle bug/rock) has access to a host of hazards as well as the coveted Shell Smash, which is a great sweeping move in any case.
Trapinch (Vibrava, than Flygon), a pure ground type but becomes a Dragon/Ground type, with excellent all rounding stats and strong attack/speed. An excellent Pokemon to use ingame
Sandshrew (Evolves into Sandslash) is another strong ground physical attacker, with access to Swords Dance
In Relic Passage;
Roggenrola (Evolves to Boldore then Gigalith), a typical rock Pokemon, with great attack and defense as well as decent hp as well as bad Special Attack, Speed and Special Defense. Still nevertheless a good Pokemon, especially against gym leaders like Elesa
Onix (Evolves to Steelix), is a defensive behemoth, and also has decent offensive moves like EdgeQuake.
~Might ad some more later