Well ill definitly have to push you far away from Roots.
Roots could be great in ELO but they are arguable the worst ELO clan now because of their banns.
I don't see how Arno is banned when has has the same ability as Redra or other 2 stars.
Ofcourse Arno does have SoA to stop maybe a damage protection ability but without Arno the 2*s for Roots arent looking good unless you want to go the CR.
Miken Moose is okay for 2 stars but i generaly only use miken and have Spiaghi as a splash.
Tuck is arguably one of the best 4 stars, And they could be great if you were able to use lets say Tuck, Burdock, Arno, Noodile Cr.
This is a great half deck for them because Tuck on the attack Manip, Burdock with full stop, Arno with damage reduction and Noodile with good strong power and avergae damage.
But sadly Tuck and Arno are both banned making an ELO play with these 2 impossible currentally.
What the Roots need if they really want to become a good ELO clan is firstly, Arno and Tuck unbanned and then some support cards! Gertjan can't do it all on his own!
But on a plus side the Roots do have alot of good 3 stars, Yookie, Noodile, Rico, Jeena etc.
Which by the way re all ELO playable cards atm (Jeena may get banned again)
So all up i try to use Roots for ELO but it is a pointless war and UR really needs to unbann these cards or release a few supports for the guys.
But remeber 1400+ with Roots is still very do able.
Well, I recommend using simple decks like Montana and Rescue. They can seem weak but they are so effective.
But the point of Elo is not a good deck. A useful deck is important of course, but the true deck is the deck that you already know the tactics. Elo is about patience. If you can play the game good and if you are patient, 1400 is possible with almost any deck. You can simply use the clan you know best
The obvious answer is that it all depends on the weekly meta. After getting a good weekly build know the matchups and what to do in almost every scenario.
Now if you are looking for one clan to use week in and week out its all preference. Like personally I use a half deck(2 of the 3) with either Montana, piranahs, Jungo. I also have a mono variant for Montana and piranahs. I feel having a combination of clans will allow you to be ready every week.
So find a clan or two that fits your style and adjust to the weekly meta.