Gear is everything. With decent items you'll solo Routine with any character, and provided that not the whole team are at level 1 Threatening isn't that difficult with some better items.
Seriously, basic 2hsword has 46 dps and I currently use a 250 dps one and I know you can do much better, more like 350.
All skills are based on your weapon dps, so if you can have a weapon with 7 times more dps than basic weapons you get 7 times better skills and regular attacks - and if you have even just basic 2 skills with a good weapon on some characters you're not extremely far behind the characters full potential.
imho most of the classes reach 80-90% of potential around level 12-13, and then you just pick some finishing touches up to level 20.