Ok the biggest things I noticed:
OKW player went early t3.. why? Flak HT from t2 is like a no-brainer vs soviets or USF, I recommend getting this unit vs these 2 factions without even thinking about it. P2 rush is way less effective than flak HT rush, mainly cuz it arrives later and is more expensive. Early puma is backfiring cuz the enemy can just skip light tanks and rush mediums then. And an early stuka makes sense in 1 scenario only: If you play double OKW (--> no panzerwerfer) and your opponents spam support weapons like no tomorrow. Vs brits it's np to go t2 as well, but here I recommend to just get 1-2 HMG34s and rush for t4, cuz early AEC and early AT gun shuts down the flak HT pretty effectively.
The OKW player had
not a single supression unit for a very long time! No flak ht, no HMG34. That means BAR'ed rifles or allied combat infantry in general has a very easy time pushing forward and winning engagements vs cheap unsupported volks and fusiliers, and it also led to the situation that the right side was un-defended a lot of times. That was one of the biggest mistakes in this match.
The hard t3 strat from your teammate (luchs into stuka) delayed his t4 very hard, and you skipped t3 in order to rush for t4, which leads to another big strategic issue here: Both of you were not even close to getting a tank out at the important 15min mark, so the soviet player could just outspam you with T34, especially after both of you lost their AT guns after they got over-extended. In 2v2 (or teamgames in general), always make sure that someone gets out medium tanks asap! You can't just sit and wait for heavies if you have big troubles with enemy mediums, you need to react
immediately on that.
This forced you to go panther, which got destroyed shortly after it has been cornered unsupported in order for repairs
No faust, no mines on the flanking routes, no support at all nearby. In the same way the tiger ace was lost shortly after.
Which was another mistake: You had enough fuel for a new panther or back-teching for stugs, but you decided to go tiger ace even tho you had 0 tanks on the field. Getting a Tiger ace in such a situation (small army, being on the backfoot) usually leads to being in an even worse spot and making it even more likely you gonna lose. A lone tiger ace without tanks to support isn't effective, and it bleeds you sooo much manpower. Just a single JT is not a viable support for a single tiger ace, it gets outflanked too easy.