New. Playing in a journeyman league

Yeah i like Koslov, just for the movement he gives. He seems like a good support caster who has so far done me proud on a few assassination runs and can comfortably panel beat a light jack if it ends up out of position. Obviously not going to rely on him killing light jacks to much once the points go up.
I'm also tempted to just run a lot of man o war instead of the widow makers in prep for a man o war theme list. Mainly because i love the look of them. Although the gun o wars and hammer o wars look a little lack luster with him.

Looks like a fun list. I'm not convinced about the Devastator on the Kovnik. Jack marshalling isn't that good in this edition - do you really benefit by not having the jack on Kozlov? The only reason I can see is to have him out of control. The Devastator will work as a zone-holde like thatr, but in a Kozlov list, so will almost any other jack and the Men of War.

I'd think about the Widowmakers you mention: Widowmakers + Marksman + War Dog/min Mechaniks is 15 points on the nose, and gives you a little ranged presence to deal with annoying solos, charge blockers and the like. The WM also work nicely with Tactical Supremacy (which stacks with the Marksman's Swift Hunter). Mechaniks are great with Kozlov, as almost everything in the list is repairable, and the feat means much of it survives to benefit from repair.

If you're worried about an independent zone-holder at the 50 point level, consider the Drakhun you mention (maybe replace Devastator with Drakhun + War Dog + min Mechaniks). It's fast enough to get to a zone early and very tough, even without Kozlov's feat. Essentially light-jack levels of ARM + boxes (but perhaps more survivable due to how the dismount rule works). There are some shenanigans you can pull using the placement of the dismounted version to sometimes stay alive a little longer. Also a really great model.

You're right about the infantry jam. Might be less of an issue in a journeyman league formet, simply as large units are more time consuming to prepare. It's generally something I find Kozlov doesn't handle that well, at least how I build him.

Honestly, i'd take a unit of MOW Demo Corps + Kovnik, MOW Shocktroopers+UA+Kovnik, two units of Max Mechanics, and something for 5 points, but that's expensive $$$wise.

fair. plus i'd have to do a lot of conversion work to get the second Drakhun looking different.