M2 Light Tank

"the Hispano-Suiza Birgikt gun does more damage and has higher penetration." FALSE statement? Isn't it now a tier II gun this birgikt? yes.

The M2 Browning

I'm wondering about the .50 cal that the M2 has. It seems as if it has higher penetration values than some of the 37mm guns I have seen. I know the "Ma Deuce" was intended as an anti-tank weapon when first designed, but it's usefulness quickly dimished. Why would the US equip a tank with a weapon of such low power when other nations were using more powerful weapons, even if they are only 20mm?