There aren't enough troops with 230+ length polearms to impact battles in a normal playthrough. 230+ length is really, really long. I think only Vlandian pikemen have them by default but I haven't gone through all the troops yet.
I guess you could just recruit nothing but Vlandian pikemen but that gimps you in a lot of other ways.
Out of curiousity, I decided to go through the crafting pieces, spitems, npccharacters files to see check out these kinds of things. I'm not sure if I was grabbing the right info but it's late to play but if someone could confirm these it would be great.
In terms of vanilla weapons and troop using them, I have found two weapon parts in total right now that are length 230, and when it comes to length between 240 and 295.. there are 7 to 8, but a lot of them don't allow bracing.
Handles used in polearms that are 230 length exact and can brace
spear_handle_8 - eastern_spear_5_t5, empire_polearm_2_t5 (I exclude the voulges, glaives and such obv)
spear_handle_21 - southern_spear_3_t3, northern_spear_2_t3
Handles used in polearms that are 295 length and can brace
spear_handle_7 - vlandia_pike_1_t5 / thamaskene_pike_t4 / fine_pike_t4
Handles used in polearms that are under are between 230 and 295 length but can't brace :/
spear_handle_6 - western_spear_2_t2 / western_spear_1_t2
spear_handle_22 - eastern_spear_3_t3
spear_handle_23 - highland_spear_3_t3
spear_handle_24 - (lances who woulda thought)
spear_handle_25 - triangluar_spear_t3 / western_spear_3_t3
spear_handle_26 - northern_spear_4_t5 /
sturgia_polearm_1_t5 wait this is no spear
spear_handle_27 - western_spear_4_t4 / highland_spear_4_t4 / wide_leaf_spear_t4 / simple_pike_t2 / military_fork_pike_t3
Troops with weapons that have 230 length polearms and can brace with them
Aserai Mameluke Regular dismounted
Sturgian Hardened Brigade
Sturgian Veteran Cavaran Guard
Sturgian Militia Veteran Spearman
+ some minor faction troops like the Sturgian Skolda dudes or whatever
Troops with weapons that have 295 length polearms and can brace with them