So here is my setup:
Helm - Ironmight Plate Helm
Armor - Ironmight Plate Mail
Shield - Ironmight Plate Shield
Weapon Slot 1: Sudaruska (Up on the mouse wheel switches to Valiance, down on the mouse wheel switches to Callahan)
Weapon Slot 2: Callahan
Weapon Slot 3: (Empty, reserved for any extra weapon I might want to bring along)
Weapon Slot 4: Valiance
Trinket Slot 1: Elite Quick Strike Module
Trinket Slot 2: Elite Quick Strike Module
(I didn't even know that I basically had the same gear that Izola had until I started to complete missions. Needless to say, it was rather awkward whenever I saw him wearing completely identical equipment.)
I know my armor and weapon selection is terrible, but I enjoy using them and have developed a workable strategy with them. The melee ASI trinkets cancel out the ASD caused by the plate armor. My strategy in PvE mostly consists of taking a swing with the Sudaruska, shield canceling, switch to Callahan, shoot, shield cancel, switch to Sudaruska, ect. ect.
The Sudaruska does good damage and knocks enemies back far enough to make the followup Callahan shot safe. Through this process, I am able to deal non-stop consistent damage (the Sudaruska and Callahan have about the same exact attack speed and do nearly identical damage to most targets), while stunning, interrupting, and knocking back all monsters almost simultaneously. Due to the Callahan being a gun, I am also able to attack multiple enemies at once. For example, I could hit a group of Gremlin Thwackers with the Sudaruska, then switch to Callahan and shoot a distant Gremlin Mender before it has the chance to heal them. Against groups of enemies, the Sudaruska's charge attack seems to be extremely effective, causing 800+ damage with huge knockback and the chance to cause stun against many enemies at once (the most enemies I"ve hit with one charge is 15). The Valiance is mainly used to deal with gun puppies, as well as jellies, both of which prove to be the biggest obstacles. The Callahan works fine against Howlitzers though, and it interrupts their attacks which makes dealing with Howlitzers very easy.
This strategy works wonders solo in PvE, although it is rather inadequate in Lockdown. I can still use the setup somewhat effectively, but I have no real ability to play offensively. I usually just choose Defender and stay behind my team while stunning enemies with Callahan and discouraging recons and enemy gaurdians with the Sudaruska. When I'm facing an enemy alone, my only real hope for getting a kill is to stun them with the Callahan and then rush in and finish them with the Sudaruska. That works fine, however it can be tricky to hit the enemy with the Callahan, so more often than not I never get the chance to stun them.
I've been trying to get a good ASI UV on the Sudaruska through Punch (for the purpose of being able to play more competently in Lockdown), but all I've been able to get are low enemy specific damage bonuses.
What I want to ask, is whether or not an ASI UV would be worth putting on the Sudaruska, and whether or not I should consider choosing a different secondary gun other than the Valiance. Any additional advice or input beyond that is also appreciated.
Sudaruska is simply outclassed both in speed and damage potential by Divine Avenger/Gran Faust.
So is valiance agaisnt some well used alchemers (preferable voltech and shadowtech).
Of course UVs will help you if you already enjoy your current set, but there are better easier-to-use options out there.
For example, you say you use the sudaruska to push enemies then finish them off with Callahan when alone. Had you used a GF and some damage bonus, a single combo is enough to kill gremlins/jellies, making the knocback and your gun irrelevant.