The two major benefits of a scout are spell evasion and critical hit. Spell evasion really works great for arials since they tend to mitigate exploitation of theuir vuln by melee very well with their insane dodging and there big weakness is usually invokers. Fire giants are in a similar boat (not all that many cold based melee weapons of good average out there but a number of area cold spells).
Critical hit is great for a lot of situations the only problem is that if you are using it then you are likely inflicting a fair amount of damage without preventing escape. Most experienced players start to think retreat when they are taking significant damage so having something like entwine, parting block, cutoff, striking cutoff, or the dash legacy will likely add to the effectiveness of having critical hit. Also keep in mind that critical hit is pretty close to just a normal hit vs an unprotected foe(it doesn't totally bypass ALL forms of dam redux but most) so the harder you hit normally the more effective critical hit will be.
Some ideas would be a giant warrior with trapping and chilling or cry using a 50 lb weapon to land oblit criticals (still will take a few of these to bring down most people). A thug thief. a whip/dagger arial (entwine and/or hurl throat before criticaling).
