I wish someone would. Since BTS, I have been going with barrage + accuracy for most of my siege, on the theory that they'll be decent wall-busters and collateral damagers. But I'm not sure if City Raider (or even Flanking or Drill) isn't a better way to go for the city attackers. I am finding my barrage/accuracy siege units rarely survive when attacking.
I used to go barrage+accuracy, but lately I've been going more towards CR+accuracy for a few units and CR2+ for the rest. I got tired of seeing multiple barrage units be unable to do any damage to the toughest defender in a stack. Sure, the other units in the stack take lots of collateral, but that bloody longbow on a hilltop is still laughing at 6.0/6.0 and destroying everything that tries.
If I go with CR, the first cat will usually get at least one hit. Then the next cat is facing a different longbow at 5.5/6.0, which makes things a little easier. The third cat will be facing an even weaker opponent and will have something like a 25% withdrawal chance, the 4th cat will be above 50%, and later cats will be even better, often 95%+.
With all barrage, the 4th cat might still be looking at an undamaged defender and <1% withdrawal chance.
With swords/cats against longbows, I like to have 3 or 4 CR1/accuracy cats to take down defenses quickly, and at least a couple of CR2 cats. I can usually spend one turn bringing down defenses, and the second turn suicide the CR2 cats to blunt the toughest defenders so the CR1/accuracy cats will be able to continue with decent chances of survival. I usually lose the first couple of CR2 cats, have a couple of badly damaged cats, and the rest of the cats need one turn of healing or aren't damaged at all.
Of course, this does leave me with a fairly ineffective siege train if I have to hit a stack outside of a city. But I don't often need to do so when I'm on the offensive. When at all possible, it's best to leave units unpromoted until they're about to attack, so you can pick the best promotion. A unit at 5/2 experience can be used to bring down city defenses, weaken city defenders, or do lots of collateral to a stack in the field. A unit at 5/10 experience can only do one of the above effectively.
It's just hard to get out of the habit of promoting then as soon as they get the experience ("Oooh! Blue Sparkles! Must promote! Shiny!")
Zienth