Looking from a different angle.
If common is paid assume $2.00/share, the pref. gets FV.
However, if A>L in a big gap (i.e. assume A=30B), by some reasons, old common might be wiped out due to BK11, then pref. is not guaranteed 100%. Trust me the debtors are SxB, will screw you up anyway. We need EC on board. Susman gets paid, we get paid. Common gets paid, we get paid.