Best single target melee skill: Double strike vs Heavy strike?

Hi everyone, I'm using Marauder with a 2 handed mace. I've been using Heavy strike for my single target damage. Of late I have been wondering if Double strike actually does more damage than Heavy strike?

Also, I am supporting it with Multistrike. As you guys might know, the knockback might cause subsequent hits to miss. The only good thing is 3 multi-heavy strikes have a high chance of stunning the target.

Should I change to Double strike? Especially when it comes to pure damage. Or is there a better single target DPS skill for melee?

Thanks.

2h melee is one of the lowest damage outputs among decent+ builds. It is also the least tanky one. It just isn't very good.

But out of those with multistrike double strike is better. Without multistrike heavy strike is decent for solo play.

Well yes, I kind of realised it isn't great defensively, but I've been 2-handed groundslamming for 80 levels and I'm not sure how to change. Anyway my mace has 6 links, so I guess it's good for something.

So is it recommended that I change from Heavy strike to Double strike?