Increased damage output against buildings
That was considered a speciality of the unit line. And in Feudal the MAA are actually quite solid in that job. We rarely see early feudal Palisades anymore, but when we did there was a lot of MAA play to break these. Also against many common buildings the Militia line can do a lot of damage. If you have enough of them.
But opposed to “real” Siege the line isn’t an anti-building specialist. And shouldn’t be as it is a line that is also decent in combat. We also see at later stages of the game that even though the line is decent against buildings if it’s played there is often the Siege component added (often Rams). Considering this there is also not a real requirement to increase the anti-building damage output. Funnily enough the anti-building damage of the later stages of the line is probably even holding it back. There is no space in the midgame for an easily accessable line that does both: fighting and raising buildings. Old Arambai got reworked because it was too good in both Adding Siege is a core path of the midgame and should be done more in low elo aswell instead of attempting to use a single line for all purposes.
There are only 2 anti-buildings things where the line could be better: A) The basic militia is really bad against buildings, especially Palisades, this could be improved. As it’s one of the main factors why drushed do so little rn. B) Against Stone Defences the line can struggle a lot, funnily even more than stuff like cavalry. It takes too long to break through because you can’t fit enough LS on a Stone Wall, so it’s easy to wall behind. And even if you bust in with petards because the line is so slow it’s usually quite easy to contain. And it takes a lot of Damage from Towers and Castles with quite low HP.
So in the end, the anti-building idea in general is probably more a C-D Tier one. I could get giving the line Bonus against Stone Defences aswell, but increasing the already existing Anti-Building damage across all could actually only make the line more problematic in low elo - cause in high elo people use the specialised Siege units for that job.