A bit of advice, from some one that has tanked for a while. If you are using heroic strike as a tank outside of a raid or being very geared, probably with windfury, you are doing it wrong. You do not have the rage to be wasting on heroic strike, you need every melee attack you do, to generate rage. Replacing your next attack with heroic strike is going to set you back quite a bit on threat generation.
Cleave is also not good to use, you will be better off tabbing and using revenge(prio) and sunder. Never rend, it is not good for threat.
As for DPS with a damage tracking addon, if you are like “why cant this tank hold aggro?” and you see heroic strikes and cleaves on his damage, that is why, he probably doesn’t know. I am not telling you to call him out, but a “hey buddy, you should avoid those two skills until you are a geared 60” nudge in the right direction wont hurt.
It isn’t that heroic strike doesn’t generate a good amount of threat, it is the fact that it replaces your rage generating attack, with a non-rage generating attack, and you will have to wait twice as long to get the rage to do something else.
As for a DPS warrior, don’t use these skills ether, you are just better off not doing it. For solo questing, spam sunder, you will do progressively more damage and generate more rage for the next mob. Also, avoid rend, it is not worth the rage, and you shouldn’t be going for deep wounds or impale anyway, you do not have the crit for it to matter 45+ anyway with an axe spec and cruelty.
When do you start using heroic strike and cleave? At low gear or leveling? when you are at like 85 or 90 or more rage, somehow? Later on when you are in full epics, probably push that down to 75.
Edit: removed part that was hotfixed regarding demo shout.