elite tome drop rate?

well, i dont know if there has been any change about this, or it may just be my luck but, ive been farming chor the bladed for almost 50 times now, and all ive gotten is 5 of his axes and 2 golden scrolls, but no elite tome wich is what i wanted, is it just luck??

2 out of 50 seems a bit low, did u farm it solo or with heroes/henches?
droprate seems the same to me tbh, got a dozen while farming legendary survivor in fronis irontoe lair

it is a solo farm, e/a sliver, warrior elite tome, i might have to check irontoe, im still open to suggestions thanks

PD it is in Hardmode, and i dont have EOTN lol

Elite war. rate.

Sskai Dragons Birth = 3/10
Geoffer Pain Bringer = 1/10
Arrahhsh Mountainclub = 1/10

i tried geoffer but i cant seem to be able to farm him, i just dont find a way, any ideA?