I think this returns to that question of, why are you trying to kill p8 baal in a solo game? I mean, blood boil can, just not very fast. You can trip to akara and back easily unlike ubers, or just let your demon do more heavy lifting, particularly with a spearwoman. Blood boil has enough damage to take out any other boss and can even manage ubers in one go, but what circumstances lead someone to do p8 baal solo when you can easily do it p1 solo, or p8 in a group, or just farm literally anywhere else in the entire game in TZ P8 split games when throne/baal are actually fairly unrewarding anyway
Lister has extremely high base HP (67.8k), medium movement (8), no regen (0), size 3 stays stacked, stun attack
River Urdars have very high base HP (15k normal, 30k unique), medium movement (8), huge regen (2.44%), size 3 stay stacked, stun attack and 25% crushing blow
Spearwomen have low base HP (7.3k normal, 14.6k unique), fast movement (12), medium regen (1.22%), size 2 and constantly run to attack, and use both 3 hit jab and power/cold strike
All the HPs scale with 4.5x playercount so tz96 p8 lister hits 305k hp, urdars 67.5/135k, spearwomen 32.8/65.7k, which is why even a lowly non-unique spearwoman is still plenty tanky because 32800 hp is already ludicrously high in pvm