Miami has been known for using smaller linebackers for decades. Darrin Smith played at 215. Ray Lewis played at 225. Vilma was 215 on a good day. Nate Webster was 225. If you go down the list of all time great linebackers at Miami, most are going to be guys who weighed under 230.
Miami, like almost everyone else these days, prioritizes speed and athleticism at linebacker. Now, would it be nice to sign a bunch of unicorns who are 6’3” 245 and run 4.4? Of course but those guys are incredibly rare. So you sign guys who are 200 but can run and cover and change direction and put them in your strength and nutrition program to get them unto 220-225 after a year or two. It’s all about versatility now. Even the NFL is shifting that direction. Hybrid players who can play multiple positions and line up in different spots are the new priority.
Wait until James Williams gets on the field and we don’t know what to call him because he’s playing safety, linebacker, striker and defensive end.