Thanks for the comments Turtle.
Stakes: good point seeing as only (?) missile units have them. However, I think that their proper use involves other units and so would come under "general battle tactics" which I'll leave to the experts. Anybody is welcome to post tactics here of course, so long as it focuses on archers.
Another thing I find handy is that it doesn't matter if all your archers are using flaming ammunition, or just one of the units. The "panicked by fire attack" will be there either way, this leaves the rest of your archers free to fire conventionally, which is somewhat more effective.
This is interesting. Thanks, I'll add it to the OP. I ran a quick test...
[TATW 2.0]
Me: two Eldar Archer units, side by side
Enemy: two Snaga Skirmishers (OotMM, not known for their good morale)
I ran the scenario three times: 1) both firing flame, 2) both firing normal, 3) one of each. Always firing at the unit that was not the general's one. The table shows how many volleys were fired by the time that unit routed, and how many of that unit were still alive...
| Test | Type 1 | Volleys 1 | Type 2 | Volleys 2 | Alive |
|---|
| 1 | Normal | 8 | Normal | 8 | 34 |
|---|
| 2 | Flame | 5 | Flame | 5 | 97 |
|---|
| 3 | Flame | 4 | Normal | 7 | 79 |
|---|
Flame+Normal caused routing the
fastest: the time it took to fire 4 flame / 7 normal volleys (as opposed to 5 / 8 in the other tests). It also used fewer arrows than Normal+Normal (11 volleys vs 16) which is good to know if you need to conserve arrows for use on the other enemy units. Note that Flame+Flame only used 10 volleys.
It's only one scenario (open field, 2x2 units, etc.) and one test each so perhaps too early to say "scientifically proven". Looks promising though.
The way I always cured archers deciding for themselves what to shoot was by cancelling autofire then hitting backspace to cancel their current (seemlingly self given!) firing orders, then click on the enemy I do want dead.
The fast forward sign appears for a few instant when you double click on the target when in range (hit pause first and you'll see it on the unit cards, there is still the white bow symbol). But a few rare time when I select a big group of xbows (like 6 or more units) and order to fire the fast forward sign does not always appear and they carry on shooting on the previous target. I don't have that problem wih 1 or 2 selected units.
I tried both of these techniques but I still get the same result: not all archers fire at the target that I give them. What I did notice, however, is that one of these techniques seemed to
help (I don't remember which one - I was trying a lot of things). That is, they were now all firing
toward that target but one or two were firing at units
near the target.