The Leafs lines make a lot more sense now that Tavares and Nylander have been split up, but our 4th line still lacks any sort of identity. It has Kampf, but it's not really a defensive line. It has Reaves but it's not a gritty, crash and bang line. It has Gregor, but it's not really an energy line.
Each player serves a very specific role, but in combination they don't really make a lot of sense as a line in terms of accomplishing anything. They're not a shutdown line but they don't really drive play or cause havoc on the forecheck either.