I literally just walked into Skyhold for the first time. Blackwall seems to be outshining the entire team and Bull is too fragile an alternative, even Sera despite me having all the poison abilities and the first three in archery.
Playing on Normal right now.
Skyhold means specializations, which means now you will be able to hold your own. Only Sera can outdo you, at least as far as damage output goes. You can just swap Sera out for Varric if don't like the competition -- not that Varric is any kind of slouch, you just have more options with putting him into a supporting role, if you want.
I agree with @ottffsse, Rift Mage specialization is the easiest to play in the first PT and gets ridiculously powerful around level 16. Knight-Enchanter is arguably more powerful right from the start, but playing KE optimally means paying more attention to detail. It's like the difference between driving a Hummer (Rift) vs driving a Bugatti Veyron (KE). You can drive either one, but you are not going to get the maximum performance out of the latter without some training and skills. Whereas with the Hummer you just point it at something and run it over. 
Necromancer, as mentioned, works better in collaboration with other party members, but that doesn't sound like what you want.
And you should respec when you get your specialization in any case. You'll want to move points into the specialization.