Orks are in a similar position - even worse now that the new Codex removes most of their saves, IIRC.
Fleet of Claw should help to some degree, reducing the amount of time that you're not in combat. That won't help if you're charging head-long in to a load of Heavy Bolters or other rapid fire weaponry.
What armies are you facing? And how much use of terrain do you make?
The main ways to keep a horde army intact enough to kill enemies at the other end are:
- run around/through the scenery. If they can't see you then they can't shoot you, and with the Fleet of Claw rule then you won't be penalising yourself too much for doing it
- Shield your tougher units with lots of cheap and inexpensive stuff. The Orks use Gretchin as a living shield to reduce the Ork casualties, but a similar tactic with Termegants and something tougher behind them should work.
- Call in the big guys. If you've got a horde of small critters or a couple of big critters then there are a couple of alternatives for your enemy: 1) target the little ones and leave the big ones to smash things, 2) target the big ones and get overrun by little ones, 3) try targeting both and hope that splitting your fire power doesn't result in them both getting through.
As for the entrenched stuff, unless it is also the stuff that has the most dangerous weapons (e.g. a heavy weapons squad) then I'd potentially be inclined to ignore it. If it is entrenched then it has a defensive advantage and it wants to use that in its favour. If you don't fight on their terms and skirt around them then they have to come out of their cover and fight on your terms. If a vehicle or heavy weapons squad elsewhere poses a greater threat then go for it rather than for the entrenched squad.
Depending on the army, the terrain and the experience of the general then you should be able to achieve 50:50 or better. It can depend very much on luck as well, though. I had several battles where dice rolls just didn't seem to go for me, but being an Ork player I didn't care too much because [i]da boyz had fun fightin' da beakies[i]