It's not like we're doing anything else with the Elite slot.
I've done somewhat similar things with a pair of DS'ing 5-Man Scions... with a pair of Plasmas each. I literally drop them somewhere they're unlikely to be targeted, and use the Plasma for support fire, ideally sniping the rear armour of something or just plinking away at an MC.
Like you said, if you aren't a serious damage threat and you aren't sitting on an objective, who's going to send a 200 point unit after a 50 point unit in the middle of not-scoring-an-objective-ville. I didn't like the idea of a complete non-threat unit, but that's just me. You're absolutely right in taking 3x3 Ratling squads. Hell, spread them around on objectives you probably wouldn't make it to, and force your opponent to deal with them.
If you take one and hide it in his DZ [can be hard to do, if your opponent spreads out] you're spending 30 points for a victory point, which is a fantastic trade.