A nice article covering one of those basic vehicles of the game.
Don't forget the possibility of flak ammo. A five point hit is a fairly serious problem to a lot of thinly-armored VTOLs (which would is most of them in the Succession Wars) or your average conventional fighter. If you don't have Partisans handy - and a lot of militias either don't own them or won't have enough to deploy them too widely - a Scorpion or Vedette battery may do in a pinch. Two point hits are still slightly annoying if you blunder into 'Mechs or armor but won't inspire the enemy to put as much attention on the tanks if they're supporting something heavier.
The natural comparison for me on the Scorpion has always been the Vedette, which has the same armament but a higher speed and 50% more armor on twice the tonnage (which illustrates the inefficiency of the ICE nicely). Vedettes are cheap cavalry tanks, Scorpions are garrison and infantry support units. If you've got infantry mounted in APCs (especially the heavy tracked variety which is also 5/8), Vedettes are an excellent companion but Scorpions make good, cheap companions to mechanized or motorized infantry.
Looking to other "budget" hardware, Scorpions can also accompany Hetzers, Goblins, or Bulldogs to provide either ranged firepower (AC, LRM) or extra close-in crit-seeking (SRM) depending on what you're after. Better yet, all three of those units are widespread and make great generic militia opponents if you paint your minis in camo instead of parade colors.
You could also do a version with twin Thunderbolt-5 missile launchers. Same range, same damage, indirect fire.
Edit: Actually more damage if both missiles hit.
Actually the range on a Thunderbolt is 6/12/18 with a minimum of 5 and notably Thunderbolts are at half damage inside their minimum. MMLs have SRMs to address that problem. Thunderbolts have a tactical niche but it's a very different role than the "jack of all trades" capability MMLs bring to the table.