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?