Roux, Petrus, ZZ(with many of it's variants), theoretically CFCE all have cubers reaching sub 10 times with it AND have less algorithms to learn than CFOP has.
Although I don't know where you get the 20 from. PLL has 21 algorithms and OLL has 57.
Petrus and ZZ are, in their most basic form, having 7 OLL cases and 21 PLL so your needed algorithms would drop from 78 to 28, although many opinions saying this form of Petrus/ZZ is not worth it; sub 10 is still archievable nevertheless, but definitely harder than with other, more algorithm heavy variants.
Roux, on the other hand only has 42 cases for CmLL. If you are REALLY bad at remembering algorithms(which I don't believe, you're likely just unexperienced) that that can drop to 7 OCLL and 2 PCLL cases, totalling 9 cases, doing it 2 look.
You might wanna give CFOP F2L, Roux F2B, ZZ F2L and Petrus 223 (basically the First two Layers part/non-Algorithmic part of each method) a serious try for 1 month each and pick the method you like most a try, worrying about algorithms later.
(I am not going to try to argue if 4LLL for CFOP or 2 look for the other methods is better overall with the rest of the solve in mind. They are all inferior versions of the advanced methods where there is a lot of discussion and analytics done already.)