Spririt wolf question

Can you tell me when it's best to cast spirit wolves? I've read guides where it says to cast them just before the start of the fight, while others suggest waiting for the trinkets to proc. Can anyone help me figure out which of the two options is better?

After trinkets proc for maximum AP/haste and fee seconds before Heroism/Bloodlust is ideal situation. If you flow of fight is predictable and will last 4+ minutes, you cast them at start and before Heroism/BL at end.