Well after watching it,
You had all the right tools(for the most part, see below) for the way the ostheer player was playing, a mortar halftrack pack howie combo with the stuart is the best route. Of course you lost the halftrack and the stuart to just innattentativeness, thats to be expected as you're new.
you had an huge advantage most of the game.
And it wouldve been an 'easy' win for you if you had just..
Bought an AT gun
The US AT gun is extremely good versus bunkers, killing them very quickly. This game you overlooked the AT gun altogether, opting for 2 pack howitzers instead.
Literally all you had to do to kill a bunker is move a squad into position for vision(even if they get pinned) and then fire your AT gun at it a couple times until it dies. Easy. And you still have an anti tank gun.
Alternatively you can attack ground and kill it through the fog of war without sacrificing a squad.
OR you can move a squad up out of the bunkers arc of fire, and spot for the anti tank gun. anyway you catch my drift? Bunkers are ez. And you countered the MGs pretty well for being new. So thats that. Youre on your way.
However,
Someone must have told you the M8 Scott carriage is good
Its actually
horrible and a unit you should actually
never buy
Matter of fact buying it lost you this game more than anything. You were doing fine, had most of the map, and you had him confined in. At around 8 Command points you buy a M8 carriage, which did absolutely nothing as expected.( Its a REALLY SHIT unit. One of the worst in the game by far in its current state.)
So...what do you do then you ask? You had picked Infantry company, which has the M7 Priest in it, that unlocks at 9 command points and is infinitely better than the M8 motor carriage.
So, as you expect, in that situation, buy the priest artillery ALWAYS. The M8 is basically a pack howitzer on wheels that costs an obscene amount of fuel for what it is.. So just buy the normal pack howitzer, that costs no fuel before 9 cp if you want arty, and once you hit 9 cp, and find yourself needing bigger guns buy yourself some real artillery in the Priest.
You couldve had a sherman alongside the priest as well, which wouldve meant gg no re.
In general
You let those mortar halftracks live happy lives.
Be a predator. Be a crocodile in the water.
If you see an opponent went for double, sorry, TRIPLE mortar halftracks, just hunt them down with your stuart.. I MEAN HUNT THEM DOWN like a SAVAGE LION...use the stun shot so they dont get away..., ez kills.
This is how mortar halftracks feel around a stuart
If you hit a mine(BUY SWEEPERS and suicde the squad if you have to to find the mines) buy another stuart and try hunting again. Your opponennt dropped 120 fuel into...halftracks. So even if you lose 2 Stuarts and the sweeper, thats a great trade and will go a long way towards winnign the game.
He has no indirect anymore and his tech is delayed to high hell, so you win right there.
Your micro couldve been better
But im not gonna roast you on how you lost your mortar halftrack. better micro just comes with time and experience.
regarding micro in general, If after a while you're still not 'getting it', watch one of the streams on the livestream list to the right and look at how people micro and handle their units, and apply it to your own play.
In addition, if you like seeing the whole picture, download replays from USF players from the replay section and watch them as well.
Even further... you can also check the LiveGames feature in game and watch the highest ranking replay at the time and watch how they handle units.
Combine all of that... and you should be fine.