Yep, I hear ya. Just depends on your play style. I frequently like to run 90-100% melee squads. I've run a squad a couple times where my only shooter on the whole team was Captain Panaka.
And Mara is actually an awesome ranged threat with Mobile/Cunning/Twin. Plus, if you're using Kyle/Jarael/TBSV, then you have the TBSV for a good ranged threat as well. You use a Mouse Droid up front with Kyle/Jarael and keep the TBSV safe in the back.
Dash at +14 is definitely nice though. I think of it this way. People throw Rex into a squad, even if there are no other order 66 pieces in the squad, simply because he's a great shooter. Well, Rex costs 33 points. Dash + Jag costs only 5 points more, and you're getting a second activation (so, similar to Rex + Caamasi). And now Dash is actually +2 higher than Rex as well. So, I think the Dash/Jag combo is every bit as viable as Rex in Republic squads, no doubt about it.
If you got Dash + Jag, and then you also have Wicket up near the opponent.....Ouch.