Any good tribes to turn into a merchant republic in 1066?

As a first note,i don't have any DLC asides from the republic one,so no pagans etc.

I like playing merchant republics,and wanted to try turning a tribe into one and playing through there.

The problem is that all the christian ones seem to be in horrible positions for it.

Alodia quickly gets inherited by Makuria if the RNG doesn't favour it,and even if it manages to get a dinastly going,its quickly surrounded by two different powerfull sunni states that holy war CB before you have time to get centralization laws up,and you can't turn into a MR if you turn into their vassal.

The other two nubian tribes just get wrecked by everyone around them.

That tribe over Georgia just gets eaten by the Cumans.

The Rus tribes might be solid,but its such a dynastic mess that i'm reluctant to even start playing with them.Not to mention,even if i start conquering with them,Visby already holds that trade area.

So,is there any trick to doing it with any of these,or some tribe that i didn't notice,or should i just get the charlemagne DLC?