In taking down Joseph Smith’s dictation here, Oliver Cowdery initially omitted the also, but almost immediately he supralinearly inserted it (there is no change in the level of ink flow). Throughout this passage, Alma frequently uses also in his arguments against Korihor, especially in conjunctive pairs:
The critical text will therefore maintain the also here in verse 41.
Summary: Maintain Alma’s characteristic use of also in Alma 30:41 and elsewhere in his debate with Korihor.