Mica the Machoke - She's filled in very admirably in overseeing projects ever since her mother's passing. Confident and willing to do what it takes to complete a project, she's a very no-nonsense, hard worker.
Marble the Machop - shy and not all that sure of herself, she's often seeking Mica's approval. Things have gotten busier for them ever since Mica had to take over the role that their mother used to fill, so Marble doesn't quite get the attention she'd like. She's not all that good at construction work yet, but she has strength that all Machop are known to possess.
Mason the Conkeldurr - Father of both Marble and Mica, and uncle to Quarry and Chip. He's a Pokemon of few words, though he does care very much for his family. Apparently, he came from another far off land before arriving in Steel City.
Quarry the Gurdurr - Cocky, arrogant; he and Mica do not get along well. They often have different visions for projects they undertake, leading Mason to try to separate them as much as possible for any work they've undertaken.
Chip the Timburr - Tries to live up to his big brother's (Quarry's) image, which leaves him actually insecure about himself. You wouldn't know it from how he acts!
The construction group was founded centuries ago by a Machamp family who has continued to inherit it over the years. The semi-recent construction accident with Mica and Marble's mother has left the family without a good backbone, as Mason's not very good at orchestrating the family to act in a productive way. This leaves projects taking longer than they normally should while Mica and Quarry argue over inane details about any given project.
(A special thanks to ~Nacome, who I forgot to link originally, who inspired this idea!)