The reason they are picked in small scale is their durabillity, having both AoE detaunt (even tho it requires a tactic) and high armor makes em alot more selfsustaning since they don't really need a tank to switch guard to them if their in trouble at the same rates as the other healers do. So this gives the rest of your group (tanks and dps) able to play with more tunnel vision as they don't need to conistantly check if their healers are in trouble and this increase the efficiancy of both tanks and dps aswell. I'm estimmating that disabling the detaunt abillity when using a Chalice/Tome will fix this problem . The casttimes are not the deciding factor in small scale. If it were every group would run 2xRP or 2xZE due to instant cast heals as it tends to more about focus down 1 target at a time. In large scale groups DoK/WP are manidtory but they are also much better complimented by the other healers then those healers compliment DoK/WP in small scale. The consistancy and cast times is what mathers here. DoK/WP shorter cast times just makes the slower casting healers from the other classes work. They compliment each other. You run into problems when you have groups of for example Shaman+Zealot or Archmage +Archmage But thats not due to DoK/WP being to powerfull. Its due to the other classes group heals are to slow and that makes those composition's unrelieble as group heals with long casttimes are also more prone to interupts setbacks and castime increasers. The problem is not with the DoK/WP, the other healers are just to weak in large scales settings without them and can't preform their tricks like Morale Boosting and spreading out HoT's for armor proc buffs etz. If you wanna break this you need to boost the other healers abillity to effectivly groupheal. Nerfing DoK/WP isn't the sollution for this.1) Why cast heal WP/DoK are mandatory, in both small and large scale.
Covered this in 1 and 32) How that mandatory status is to be broken.
Remove Blood Offering/Supplication from the game completly. This is the skills that enables DoK/WP backline healing without being in melee range. Instead add to mechanic. Whenvever you hit an enemy with a melee abillity you gain 15RF every second for 5 seconds (Can't refreesh itself Designed to be used by Smite/Essence Lash) This will force the DoK/WP into 50 feet of enemy frontline to be able to pull of the same regen rates as with BO/Suplication and actually warrents you having better armor and casttimes as you're forced 50 feet close to the fight then other healers.3) How their skillcap can be raised. My view is that this can be done in small scale by linking the melee healing to the casted healing, as at present, adding Divine Strike / Consume Essence and increasing the AP cost of Sigmar's Radiance and Transfer Essence. If you have an alternative suggestion to increase the skill requirement given what the class has, feel free to venture it.)
Wo what imo think gonna work (for cast healing that is) is the following:
Disable detaunt while wearing a Chalice/Tome
Replace Blood Offering/Supplication with a on hit SE/RF regen proc on melee hits and increase AP costs of Essence Lash/Smite to around 100 AP
Increase other healers groupheal capabillity.