xZLib belongs to an old XTool version. If you use current XTool version (0.8.9 I guess) use xtool:zlib instead (maybe reflate is a possible option aswell, I don't have the game).
srep is there for deduplication. Actually you just need srep.exe (64bit version) and then use xtool option :dd1..5 (where 1 is fastest and 5 is slowest but might get a few more duplicates. Default is 3 and in my humble opinion this is peak most of the time).
exe and delta are freearc built-in compressors (honestly I don't really know what they do actually).
lzma2 is from 7z archiver so you need 7z.exe and 7z.dll files aswell.
Code:
arc.exe a archiv.arc "C:\Bionic Commando" -mxtool:zlib:dd3+lzma2
You can also go with freearc built-in lzma in addition with 4x4 instead of lzma2 to use up to 16 cpu threads.
Code:
arc.exe a archiv.arc "C:\Bionic Commando" -mxtool:zlib:dd3+4x4:lzma