Right, it has 2 warheads, but the warheads do not act anything like a HEAT charge, they are completely different beasts.
It forms 2 ballistic penetrators (these are solid mass plates compressed to a bullet(ish) shape, not the super heated/pressurized "jet" of a HEAT warhead. The extent of their similarity is the shape of the explosives within the missile upon detonation. It is at that point that it ends.
These 2 "warheads" are not dual charge in the sense of a HEAT round, with a "spoiling" charge to trigger ERA. It has both going off simultaneously at different angles to ensure a hit as the missile overflies the target.
As far as ERA, there is no "jet" to be disturbed. It is a solid mass kinetic penetrator, same as any AP round fired from a gun tube.
Here is a photo of a "formed" EFP.
It does not possess the penetration potential of a similar sized HEAT round, but that is not needed to punch through the roof, and largely nullifies ERA same as a SABOT. If it does penetrate though, it has a higher damage potential, creating a larger breach, spalling and all the other nastiness created by a traditional KEP.
As far as in game, the considerations are, how does the 2-B currrently interact with ERA? It should be performing as any other solid AP shot. After that, it's penetration potential. Unless a TA munition's Pen value is divided, the 2-B should be a great deal less.
Now SP clearly must make approximations (both in direct and indirect ways). Simply wondering if as is, it is the best one for this system, and if it is both over & undercapable under different circumstances as a result.