Ok here is my analysis, I paid most attention to your unit composition, a little to your mate and none to the enemy.
There were a few crucial mistakes:
Doctrines:
I think you chose the doctrine too late and is too weak in general in teamgames. You both had heavy AI doctrines but more importantly no bombstrike!
A bombstrike is the most effective way against elephants. You need a simple guard squad to button and bye bye.
You opened with 0 conscripts, building cons midgame is pretty much a waste of mp. You are better of with guards or purely atguns and maxims even. Your cons ,without at-nades/Molotov, face vetted units.
Howitzer:
It was a good idea, you almost took the elephant out with it, had you just sacrificed one tank or atgun to chase it. But the elephant doctrine has recon and stuka, probably the easiest way to take out howitzers. I wouldn't rebuild them let alone more than 1.
T34:
Why did you stop building t34s? Granted this map heavily discourages t34 play and you didn't have any call-in tank. So I can see why you did that.
But it is the only option of dealing with an elephant here
If you don't have bombstrike your only option is t34 ramming. You could easily get in from the left flank with 3,4 tanks and ram it from the back. This allows atguns and su85 to move in
Hope this helps