Doviello:
The Doviello don't get many buildings, and are poor tech racers. Therefore, the best strategy is to keep your opponents weak right from the beginning - you should ignore religions and head for Bronze Working, only filling in low cost builder techs as necessary to keep your cities growing. You should also look for opportunities to take weakly held enemy cities while still in the very early game, either to raze (usually) or to add to your empire (if they are in very good locations that are easy to defend).
Generally, I will create a small core of high-production cities and then develop them, rather than expanding. I will try to found Pact of the Nilhorn so that I can get the Giants, to use as siege machines. Other than that, I'll only create Markets and Courthouses - everything is subordinated to military production.
The idea is, let your opponents do the hard work of founding cities, religions and the like - you will take what you need over the corpses of their troops. You need no fancy Civics - go cheap cheap cheap as otherwise maintenance costs will cripple you. You need no Adepts or Priests. What you need is melee units, and plenty of them.
Once I have Bronze Working I will have one of two choices:
If I have Copper in my borders, hook it up and start cranking out Doviello Axemen in every city. (Because you do not need a Training Yard to create them, all your cities can join in the fun right away).
If I don't have Copper, I need to get it as expediently as possible. I start building hordes of whatever my best unit might be (usually Hunters) and take it.
After Copper is hooked up, almost constant warfare is the theme. I attack the most powerful enemy civ first, and use units up almost constantly - your economy is weak, so it is better to fling your units into the fray, rather than nurse them up to high level. Dead units cost no maintenance

I will attack at low odds, if I am reasonably certain my second attacker will finish off the enemy - not to say you should be reckless, but your first concern should be killing the enemy, not protecting your own.
Once you have taken 1 city from your enemy, decide if you want to raze it or keep it (usually raze). I generally raze about 2-3 cities for each one I keep - there is a great danger in over-extending yourself, so you want to grow slowly, and keep your opponents growing even slower.
You want to head to Trade now so that you can demand techs from your defeated foes. As soon as one war is done, start another with the next strongest opponent. Don't let the AI sit and build its military strength - you want to have it so that even if 2 or 3 of them gang up on you, they do not have the offensive forces to threaten you with defeat. Once some of your units have survived a few battles and gotten powerful, set up a strong reserve near the centre of your kingdom that you can use to kill pillagers - promote these units up a few levels, then rotate them out and use them as mop-up troops behind your hordes of fodder.
Sometimes there will be a weak Evil civ you can induce to assist you in your wars - do so, but don't neglect the opportunity to stab them in the back if they have something you need, or if you're just feeling frisky. Make sure to demand tribute whenever you can - check every 10 turns or so to see what the other civs will give you.
By the early mid-game you should have an empire at least twice as big (more likely triple the size) as your nearest opponent. By demanding techs, you should be still in the middle of the pack as far as science goes. Now head to Iron Working, and use your Battlemasters to conquer everyone - just keep pushing them out and out and out, always attacking, isolating one opponent at a time if you can. Get siege weapons and build the War Machine last, and use it to finish off whoever is still alive, although by this time you are usually so far ahead you can afford just to overwhelm people with stacks of veteran killers.
The key is that you must never stop warring - if you are at peace for more than the 4 to 6 turns it takes to redeploy your armies for another offensive, you are not being aggressive enough. You want to win by domination by no later than the late middle game, before your rivals completely outstrip you technologically.
In summary, play them as the barbarians they are, and you will be rewarded. If you don't, you will be marginalized and beaten.