While binary may be suitable on a gun range where one AT gun is shooting one round at one target, it does not capture the multitude of attack angles an AT unit is going to deploy against a tank force that will include a multitude of different tank types and variants. Even undersized AT guns made tank units bleed and slow down. When a commander knows his guns cannot pierce the front of the tanks he expects to encounter, he is going to adjust for that. There are solutions. He will not be 100% successful, but he will not fail 100% either.
I know it is outside the binary discussion, but AT guns were also very handy when attacking dug in units, fortified positions, like forts, urban areas, mountains, and about anywhere the infantry needs some close support, but tanks cannot be risked and indirect fire cannot be used due to danger close situations and the arc of the shell being ineffective. I know if I was leading an infantry battalion in the attack I would wheel my AT assets up to take out buildings, MG positions, etc... It would be criminal not to. Maybe the game could give AT units some bonus to the attack against such positions. They are amazing assets and it is a shame that in SP the only smart move is not to build them.