3rd rb doesn't have much of a chance to see any time on offense so they picked Dowdle because he's a more proven STs player - helps being a veteran.
Down roster players need to play special teams if they want to make the field on gameday. And if you're just not going to make the field on gameday, you're not making the roster unless other teams are gonna poach you from the PS.
Gotta be useful. If you ain't great at one thing, you need to be working at being good enough at multiple things to justify a game day roster spot. That's what opens the door to a career.
Noah Brown is the poster boy for Making Yourself Useful. How many WRs give a crap about blocking? But that got him on the field with the offense, *after* his special teams got him on the gameday roster.
Rico Gathers was the Anti Poster Boy. Had physical gifts to block, but always focused only on his downfield receiving skills, dreaming of being Randy Moss, and only mentioned blocking years into his time here. If he had focused on being a blocking TE first, he would have gotten opportunities on offense.