unfortunately no the write was not joking.
if u really wanted to use a merc go with an a1 merc since it can use inner sight and lower their defense, thus increasing your chance to hit. or go with a2 offensive for blessed aim.
edit: for got to give u items u should use.
a1: 3 soc mask with 3x 9 max jewels in it (u could substitute biggin's bonnet here if u want some life on your merc, but 15 life is not going to add much); 3 soc light plate with 3x 9 max jewels. 3 soc hunter bow with poison dmg on it or 3x 9 max jewels (note: i'm not sure if max jewels work in missile weapons).
a2: 3 soc mask with 3x 9 max; 3 soc light plate with 3x 9 max. rare polearm with 2x soc and decent mods (lightning, cold, pd, ll, ed, and eth would be best but the chances of all that being on the weapon with 2x soc is going to hard) 2x 9max jewels or pd.