It really REALLY depends on what a nomad army looks like as it evolves.
I still think that there is a plausible hybrid Nomad-Settled civilisation that is possible. As a result, you can have settlements deep in 'nomad' territory that are used to produce a form of carbine, or light cannon - or any other form of weapon that could be useful.
After all, nomad armies are defined by their mobility, not so much simply that they have lots of horse archers. It could have an equivalent of a hussite war-wagon to allow larger cannon to be used.
I'd even go so far as to say, with a blip when the gatling gun comes along, and now where wars aren't typically fought in the same way, that you could have a nomadic army that moves from horseback to combustion engine - very light tanks and armoured fuel tankers.
I might be pushing OTHER definitions of 'nomad army', but if it is as nomadic as the mongols, then it'd be fine.
In fact, I'd go so far as to say, that you could continue a Nomad Army, supported by Western-Style forces till the modern day, in the same way that the Mongols would supplement their forces with settled levies.