What class are you, what level are you, who is your first mate, what powers have you trained, how many companion promotion quests have you finished, what companions are in your roster, how do you have them arranged, what epic talents have you learned on your companions, and what tactics have you tried already?
Granchia does tend to be really tricky. It's hard to avoid getting pulled into random fights, and the battleboards are often large and oddly shaped.
I usually spend the first couple of rounds moving my team (me & my companions) into a group at the closest corner, then wait for the Armada troops to come to us. That'll often give us a round or two to buff up while we wait, a Juju or an Armor boost.
Focus fire on one Armada unit at a time until it's down, then move on to the next one. The Marines (melee units) will often Immobilize you if you try to move past them so I usually target them first.
If you have ranged attacks or powers that will Slow the enemy, use that on the furthest unit away that you can; that should give you some time to work on other (closer) units while they're still too far away to hit you.
I haven't had a problem with the battles there being too difficult but I hear you on being forced into unwanted battles. I haven't figured out a way to get that one bird for the zeek quest without wasting time fighting a pointless battle. That place frustrates me so much. Ugh. I wish they would move the enemies a little bit there so its easier to navigate without getting pulled in.
Some of the following advice is fairly generic - generally useful vs. tough enemies giving you grief:
As Starsong suggested, it is a good idea to concentrate on someone until you put them down. If you have six opponents and do enough damage in a round to kill one of them, but instead spread that damage among three or four of them, then you have six attacks coming back at you instead of five attacks if you had concentrated and killed one.
In the fights where they are coming around a corner at you or start far away, buff as much as possible and keep an eye out for concentrations if you have a bomb handy. Make them come to you and use the time wisely. If you run at their shooters, you are hit with Overwatch; if they come to you your guys can shoot first.
Starsong suggests going for the annoying marines with Hold the Line; my preference is to take down their shooters first, since they have higher accuracy. (Also, I tend to run with a melee heavy crew, so their marines take damage from my crew's First Strikes, Riposts, Vengeance Strikes, etc. during their turn, allowing me to concentrate during my turn on their shooters). Do keep in mind you will be stopped if you try to run by someone with HtL though.
Their Overwatch ability will not trigger if you if your guys are moving through occupied squares, so you can hit their marines, and then keep your crew advancing primarily through squares occupied by friendlies, you reduce their opportunities to shoot you and your crew while you are advancing, changing targets, etc.
If you are having trouble with them dodging, consider temporarily moving Bonnie Ann to your first mate position, and have her blast them with her area affect that reduces their chance of dodging. This tactic works well against the really dodgy types.
Don't know if any of that helps, but hopefully someone can over you a useful suggestion to try.
I have done all my side quests, even going back to check every single area to make sure I have missed none. I have spent all my gold to get my companions up to the same level I am.
Yet, in Granchia, not only are the places I have to go to unreachable unless I enter at least one battle with the clockworks, I get slaughtered by them, every single time.
I have nothing else to do. All my other quests are done.
NOW what do I do?
well granchia ultimitely easy for me but..... MOOSHU IS HARD! really it is i get randomly blocked by guys that ARE LOWER LEVEL even the muketeers are dodgeing me how am i suppose to do my story line quest and my side quests if i cant kill almost anything one-eyed jack please reply to this lower there dodge please