amira l'aku"m vs. gerama: which is the lesser issur?

Given the choice, which is the lesser issur: violating Shabbos (or some other issur) through an amira l'aku"m, or violating Shabbos through a gerama? The difference between the two: amira l'aku"m involves doing a full act of issur, but it would be done by someone else who is not a bar chiyuva; gerama is not a full ma'aseh issur. I stumbled across a R' Akiva Eiger (Tos. RAK"E to Bechoros 5:3) which claims that amira l'aku"m is the lesser issur, but I do not understand his proof (he simply says see the Rosh to B.M. 7:6), so make of it what you will.