It’s a consideration, alright. I personally prefer designing for 15-30, with the sweet spot in the mid-20s. At this point, a typical character can be challenged by various threats. The info above about #/powers is spot on. Even with a few powers, choosing one of the upper tiers among the set can make a boss deadly at low levels. I paired Dual Pistols with a few forcefield set powers (including one of the better ones, I don’t recall which), and ended up with a boss character that just killed me, even with insp buffs. Also had a boss who locked you down with fire cages, then sent in shadow pets to wale on you, while you stood there, burning up. In the end, I went with easier combos, simply because there’s a fine line a fair/unfair challenge.