Security plug-ins: Best strategy?

I recently added Sucuri, Wordfence, and iThemes to my site but have no idea what the best strategy is for securing my site. I added all three because I read a review that they’re all good but approach security in different ways, but am wondering if that’s overkill and if maybe I’m slowing down my site or there’s some other negative effect.

I won’t ask what the best plugin is because I know there are a ton of different opinions. I’d just like to know how best to approach making my site safe.