I don't agree or disagree
It's a good point, because there have to be enough to do the job or they become expensive warriors. I can count on half a hand the number of times I've used anything other than the moving song, adding Terror a couple times to a single WE holding a gap. In that game, that was worth the 25 points right there, and I think I'll make more use of it in future. It's also rare I've used the moving song on a normal warrior, usually on a monster, but they have pretty decent odds of making their courage roll. So it's nice to have more than one in range, in case the first didn't work.
I guess it depends what you want to do with them. If you want to use them to move things around and create gaps, with 2200 points of opponents you'll probably need more. If you want to spread them around to add Terror to key points, that could also be very useful, but 3 is probably enough.
BTW, you have no elf blades at all...I think you need a few, maybe 4-6. They are very handy for monster chopping, or really anything D6. Use them as escorts for your heroes. You won't need too many, since you'll be so outnumbered you'll need every fight optimized, but when the opportunity presents, you'll be ready.