What is the M3/75 in La Campagne de Tunisie?

[Blackcloud6]

The 4th Edition Rules tell us:

Armored Fighting Vehicle (AFV): Any unit with a printed armor defense value (even a value of 0). This includes self-propelled artillery, armored cars, special armored engineering vehicles, armored personnel carriers, and other similar vehicles. A tank leader may activate any of these.

Tank: Fully armored AFVs with a printed armor value, anti-tank fire, and usually direct fire as well. They stack like other combat units and use Mechanized movement. Many scenarios use eliminated tank steps to adjust initiative as well as determine victory, and such step losses would include all units described above with the attendant armor symbol on the unit. So, units that would be excluded would be self-propelled artillery, reconnaissance, and APCs; while most tank destroyers would count, along with engineering vehicles like the British Crab or Crocodile.

The La Campagne de Tunisie does not list the M3/75 as a being a tank destroyer nor being open top, both of which are curious because it was a TD and was open topped.

Nothing else is mentioned in LCdT about what the vehicle is, so given only the definitions available by the rules, it is, in game terms, a tank.

This is important because the Special Rules for LCdT for tanks leaders uses the word "tank" and not "AFV" is telling who gets tank leaders: "All American, British, and German Tanks in La Campagne de Tunisie have tank leaders and armor efficiency."  

Your thoughts?