How high is your attack and defend bonus for when you start a battle? I can't win 2 wave battles on GE 1
Sure you can, at least some of them. The range unit mix is the worst but beatable. My secret is that — contrary to most advice — I have at least one of every troop building and keep them current (I often have one current age and one last age, for each type) plus I have 3 IA archers (though my LMA town is down to two of them now and might lose another before I am out of LMA).
The archers are mostly for cheap fodder, since the enemy will generally attack the weakest units; so if I know, for example, that the enemy horse archers will come forward and kill one of my guys whatever I do, I include an archer. Archers aren’t just fodder, though: with a little skill, 8 of them can take out 8 heavies even up to HMA with minimal loss/damage. They are cheap, require little space and rebuild in 2 hours — marvellous little chaps.
This means that I can look at the troops on GE and match my army accordingly. I am never fighting a mass of heavies with light infantry, I can cavalry-charge the range units and lose only one or two in the process, I can form a versatile square or triangle against any kind of melee units, and I can set an artillery barrage likely to smack down most troops.
To answer your question, on one city I have about 23%, on the other I have about 45% fixed attack bonuses. The difference is notable, not necessarily in how many units I might lose but in how injured they are at the end, or how many are injured. I am
just getting to the point where some units will kill with one hit: THAT makes a huge difference, not only because you might be able to attack more enemy (which you can’t always) but a one-hit kill means you don’t get injured by any retaliation. Dead men don’t fight back!
At the end of GE2, I will often apply a tavern boost, too, but that isn’t so useful until mid-GE3 because it doesn’t add protection, just makes you hit harder/for more. By mid GE3, the enemy protection starts to climb so that extra attack means you can still be sure of a two-hit kill.