I don't think they're that far off. If I were you, I'd level them all to about 80 first. Credits are a cheap and fast way of increasing character viability.
It looks like you have decent mods on some, but very weak mods on others. See what you have lying around that would help them. You don't need to take mods off arena toons, but if you could borrow some mods that would help a lot. Having level 1 mods on your toons is not going to work. Remember you only have to 3* it once, then you can strip them of all their mods, so don't feel like you're wasting credits by investing in mods.
I did the last tier with 3 of my jawa at Gear 5 (level 80). But my other two support my droid team so they're G10 and G8. Having a fast Engineer helps a lot, as does a Scavenger that can hit hard with the bombs.
