You are right instructions could contains mixed informations
If not already done, Upgrade to stock android 10
Allow USB flashing , OEM unlock…
Flash a custom recovery (twrp 3.6 is available)
" no-verity-opt-encrypt-samsung-1.0" is outdated
according to the XDA thread version 6 exist and is recommended no-verity-opt-encrypt-6.1.zip
VENDOR-27_ARI9.zip is useful only if you want to install the android 8 Oreo based /e/ stable build
Install the /e/ build