Chanters suffer from the same issue as SK's, and mages for that matter - there are very very very few decent people who play them; which of course could be a product of the bad PR.
Thats pretty much the case imo. The class had its dark ages where it was not really fun to play and had its slew of issues, but the population of them hasn't really recovered since then. From some of the newer enchanters who have caught up with me in game with questions, I keep a positive outlook on the recovery of this issue.
But yea, as far as raid stacking goes with enchanters:
Shared mind: I think a lot of people think of this primarily for the resists, which don't stack with multiple, but all of the rest of the benefits do stack just by putting the enchanters in different groups.
Debuffs: ok no benefit to having two enchanters here.
Curses: Absolutely no stacking issues here, you just have to cast them a set amount of time apart from each other or they won't land.
vex and super vex (aka runic2): If you have two enchanters with this theres really no excuse not to have it land every time the tank drops too low, making those stupid wipes from healer error pretty much nonexistant.
Gog/aod: One enchanter will never be able to gog/aod everyone that can be. GoG and AoD both give a 32% increase to dps on the target for the duration of it (skewed numbers on AoD depending on the class, and I believe them to be: >32% for wiz due to the nature of wiz crits (assuming there isn't wiz specific code for AoD), 32% for necro, <32% for mage unless that got fixed). Anyways, if you're up against a boss where your main support is dps, one enchanter can keep up at most 6 melees if hes only casting GoG which is way more than any individual melee is putting out for dps. AoD you can keep up 4 targets, which again is more than any individual is putting out. With two enchanters you will still have enough targets to fully take advantage of all of this.
For trash, since you're usually trying to conserve mana unless you're pushing into new content (which btw enchanters are phenomenal for, see above paragraph), you're main goal should be to pull your own weight with dps and if you can keep up 3 GoG's you're doing that. Now if you're NOT pushing into new content, and you're just farming tiers which is most guilds most of the time, there's a decent chance you DON'T need to pop gather on every boss fight which frees you up to keep a more mana draining approach to trash and popping halfway to a boss fight, which means you're DEFINITELY pulling your weight. Thats all tricky though due to med breaks and shit, theres rythm to be found with each guild. Again, totally stacking friendly to having more enchanters.
Rune: If you're in a situation where theres not much reason to do anything but chain rune, having two enchanters is definitely a perk if they can coordinate between themselves well (I wish I didn't dislike raralith too much to try this with him). If you time your runes to land offset from each other, your main tank is receiving a ridiculous dps cut making the healers job retardedly easier on those heavy hitting rape train bosses.
Anyways all of that is from the perspective of a higher end enc, meaning my mana pool and mana regen can or can close to sustain the numbers I'm throwing out here, so this won't be the case for low end enchanters. Lower end its harder to even pull your own weight with gog and such, which also I would imagine contributes to the negative connotation given to enchanters. That said, most of the group stacking probably takes place in the higher end anyways. But if theres legitimate things I'm missing here or if I'm way off factually with numbers or something, I'm open to the idea of being wrong.
Grouping is simple: charm. Two enchanters just means two people to handle broken pets, but the dps is just as good as ever per person.
Edit: Yea totally hijacked, but this bit felt semi relevant to enchanters needing added synergy bonuses.
