There's many things to say that could help.
One, Holy Paladin buffs themselves with Righteous Fury and the tanks get substantial one-on-one threat if possible because the blood beasts need to do little-to-nothing in terms of damage in order to keep that Blood Power down. The small aggro from the RF Holy Paladin will pull the beasts enough to attract it and give your range some time to change targets, snare and whatnot.
Paladins should Hand of Protection a Caster DPS when possible during a blood boil because it removes said debuff without fail. That's 8 BP prevented.
Damage prevention should be key so get the Paladin to learn to Sacred Shield people to reduce damage ticks.
Range positioning should be at least 12 yards from their nearest person while still in range of heals. Reduces the amount of BP generated from Blood Nova as well. 2 BP per person in range is deadly.
Hope this helps.
Healing is the source of life. Without it, you're left with death.