i was thinking they would become uber...
but is +120% vs cities not uber too?, its about the least descriminant promotion aside from combat, and city defense
flurries already have a lower base strength right?
+120% vs cities is good, but that once can be countered by having City Garrison, and Guerilla. First strikes can only be countered by first strikes. (And a higher effective strenght, so that the first strikes miss)
You know when you lose a battle you definitely thought you would win? Then you go to the combat log, and check the combat rounds and you see that your unit got hit 5 times in a row at the end.
Now consider a unit with 10 first strikes. The other unit have no first strikes, but its a 6 str vs 9 str battle. Your unit is at a disadvantage on the strength side. But first thing that happens in the battle is your first strikes. (I'm not sure exactly how this works, but I'm gonna guess a bit). So 6 + 9 is 15, and 6 is 40% of 15. So each combat round it has a 40% chance of hitting. Which means it will hit approx. 4 out of the 10 first strikes.
Now I ran some tests, and it seems that in most battles, the damage you do is based on 40 (which gets divided based on strength), so each hit you land will do approx. 16 damage (40% out of 40). 16 x 4 is 64. So before the other guy even gets to hit back, you have done 64 damage. Which means he has 36 HP left, and you will only need 3 more hits to finish him off.
Since he has a slight strength advantage, he will have a higher chance of hitting you, and hit harder. 60% and 24 dmg per hit, which means he will need 5 hits to kill your unit. So this battle got maximum 7 more rounds to go. According to my calculations, our first strike unit got 53.33% chance to win after this hypothetical scenario.
All I did was prove that First Strikes are more useful versus even odds or better. The unit in my example would almost be unstoppable against even odds enemies in fact. Against a unit with the exact same effective strenght, it would hit 50% of its first strikes and do 20 damage each round (statistically). Which means 5 x 20 = 100, instagib, and no damage taken.
All this theorizing about the first strikes got me thinking about the Shield Wall. How about it gets an ability that lowers the damage taken by a certain %. Maybe to every unit in the stack (maybe even when attacking from that tile).