nMA is not useful since it's very hard to actually die there and does in no way prepare you for vMA since most of the mechanics that would be one shot in the latter can actually be healed trough, or even outright ignored on normal. Ex. I did normal once while leveling a character and never bothered to cleanse the poison from spores in Vault of Umbrage until the round ended, on vet you won't last 3s.

As for the setup, it's decent, but you may end up overpenetrating, depending on what traits you have on weapons, what class, and how many CP you have in piercing. I'd rather combo Spriggan's Thorns (penetration set) with a pure damage set like Hunding's Rage, Strength of the Automaton or Briarheart. Note that most mobs in vMA have around 12K resistance so you'll have to stop slightly short of that. On classes that lack Major Fracture from their kit like Sorcerer and Templar using 2 penetration set will not end up higher than that but I'm not sure about the overall damage increase vs. one penetration + one damage set setup since penetration has diminishing returns as you get closer to the cap.

If you heavy attack the mobs you won't have trouble sustaining even without VO. Bound Armaments gives bonus damage to those. Never played Stamina Sorcerer myself, but I reckon it's not much harder than Stam DK and Stam NB which I played, so it should be doable as long as you follow the mechanics. High DPS is not needed unless you want a leaderboard score, since it allows you to skip some of the mechanics and greatly shorten the fights.

My tips for new vma runners:

If you do it without VO i would replace one ulti with overload and put dark deal on there so you can easy get stam back after one round and get a nice heal.(VO is one of the best sets for vma)

Also use heavy attack attacks. If you time it right you can heavy attack always the first mob that spawns at one of the portals to kill it.

If you are low on stam and at the end of one round try to spam heavy attacks on the last enemy.(Don't do that if the enemy can really hit hard e.g. stage 8 mini boss)

Beast trap is really awesome to root one enemy and let it die in ground aoes.

You can use sigils. Seriously do not be afraid to use them if you are not going for a score it makes no difference and there are really powerful especial if you are not so experienced in msa. (The defensive sigil reflects all range attacks and is the best sigil)

Kill adds fast. The faster you kill something the less time it has to kill you. Just find out what kills you most of the time in one round and try to focus it down as soon as it spawns.

well i have great expirience with briar + vo set + krag + lover mundus in vMA, with CP i can hit easy 9k penetration with is optimal, on other side i play stamplar and have advantage in pover of the light (+1320 pene) but evry time when i try replace VO with pene set i have huge resource managment problems, and this bonus movement speed when kill enemy on VO set proly one of best think for vMA, bc you cen rach other mob faster and they have little time to kill you. I personaly dont like spriggan set its except penetration offer only limited dmg boost. Unfortunetely here is not much god stamina set with jewelery which can be purchaset without farming dungeons, only sprigan is decent and briarhad which is best in the slot and its rly expensive ( it offer little beter dps output then hunding, but bc 5set bonus is proc oyu can have jewelery + weapons and still dont lose this bonus when swap on bow bar, and this little heal is helpfull in vMA) but if you never finish vMA before you proly spend lot and lot of time on your first run