Yeah, the gun-line is pretty nasty. When wounds is your limit, having three models doing -1 and 2W when hitting on 2s wounding on 3s and Cannons with 2 shots, re-roll to hit, -2 and
D6 damage on top of all the Handgunner, that also shoot when charged will decimate the opponent pretty quickly. I do not think either of the starter set armies has a chance against that army. The Demis are definitely the more interesting army for both me and the opponent.
I also know that one guy will be playing that Beastmen Formation where half the army arrives in your deployment zone T1. Not good for a gun-line.
Having said that, I will not be the only one discovering how awesome Cannons are. I know that one guy is bringing his Steam Tank, which is another step up from the Cannon. I know people who will be bringing full on Daemon factories. You need cannons lest this gets out of control. However, the War Altar has a massive shooting bonus against Daemons, so 1-shotting Fate Weaver should not be a problem.
There would be a third, more balanced alternative with Demi Gryphs, Outriders and one or two mounted Heroes to keep up. But balanced lists should be reserved for bigger games. Smaller games are all abour synergies and abuse it seems