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 Footman
Aserai Infantry
Aserai Mameluke Regular dismounted
Sturgian Solder
Sturgian Hardened Brigade
Sturgian Spearman
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
Vlandian Pikemen