Also, other playstyles can have synergy.
Using special arrows you can create any kind of synergy a mage can internally.
Knockdown arrow/crushing fist/battering ram/crippling strike + bully is self-created 'synergy' but in a different way.
Venomous Strike + fire enchanted weapon auto-attack = explosion
Hit a zombie then phoenix dive = explosion
Scoundrel exploskeleton + poison = explosion (using this one quite a lot at the moment)
Also does bleeding + air damage stun?