Soviet union should have no trouble to build enough Inf1941-AT1940 by mid 1941 to utilize all available tc with just those Inf-AT. That is despite Inf-AT being the most tc-efficient unit(Mtn-AT may be on par). 500 Inf1941-AT1940 in battle use 1.16x3x500=1740 tc. With -15% supply consumption from Chief of Army it is still 1479 tc. It is this Chief of Army that is worth a lot.
Anything that mitigates your amount of Inf-AT to less than full utilization of available tc should be skipped. Building expensive stuff like armoured divisions can wait till after the start of the war. It is mainly Inf-AT you need. A few Mot-Art and a maybe not so small amount of Mtn-Art can supplement your bulk of Inf-AT.
Your heavy push on Anti-Tank (AT) brigades versus ART is quite wrong. The majority of the German forces which battle to break the Soviet line is infantry (and not tanks). As such, the majority of SU brigades should be ART to give greatest soft-attack against German infantry targets. A mix of 2 ART/1 AT is OK for the front-line, but all ART on INF is probably better since ARM should be available where needed.
And your neglect of armored units to be on the line
when war starts is begging for a colossal Soviet defeat and magnificent German blitzkrieg. FYI, when it matters where it matters as regards successful German exploits, it is always German armor that races to surround and trap the Soviet INF. SU needs ARM to stop those German tank exploits... and all the anti-tank brigades on all the already by-passed SU infantry divisions won't help you there. The only exception would be if SU player dedicates some INF divisions to permanently guard against German ARM exploiting a blitzkrieg. So, if I planned to always keep some INF in Moscow, Stalingrad or other
rearward strategic place to stop the German armor that might break thru, then those dug-in divisions only having AT brigades would be wise. In fact, 1 unit in the defensive stack could have ENG brigade for max defense of those units against an exploiting corps of German panzers. Unfortunately, you miss mentioning this most important brigade totally which should be present (1 division only per defensive corps) for EVERY frontline province - especially the large corps (6-12 divisions/corps).
Lastly, your MOTs are also wrongly brigaded. Other than ARM, they are the only thing that can respond timely to a German blitzkrieg which sees the panzers racing to grab key provinces to create the conditions for massive SU defeat. Therefore, the SU MOTs need mostly AT or TD (not ART) to beat the German tanks which they will face alone.
EDIT: Mentioned ENG to complete the discussion.