1st: regardless of whatever terrain is in use, the table is still only 46" - 48" across....
If you want to be in melee you'll get there on turn 2.
Mount some units in Rhinos, land Raiders, the primaris hover tank, etc.
Maybe some drop pods.
Jump pack units.
Deepstrike.
As for ranged fire? Yes, the
BT unique units are
CC focused.
But they are
STILL SM & have access to all the ranged options in the base codex.
So if you want to shoot the foe.