The difference as far as I can tell is that a lance would go through the shields like a bullet through tissue paper and the batteries would have to go through it normally.
Also source? I've never heard that as a standard tactic before. Particularly as some ships only have lances or are just very lance heavy.
I should point out also that some ships do have energy weapon banks that aren't lances. So they'll likely figure it out sooner then you think.