So Commander, you're struggling with brits, eh? Don't fret I'll walk you through winning as this faction! The shrek blobs of doom, pak walls and etc shall be a distant memory before too long, kappa.
The Build Order
Build orders are very simple and straightforward.. But, I'll outline the one this guide focuses on here for you.
The general idea behind the build is simple, rush for a very important part of the map with your first IS whilst using your second IS to cap. Your IS, usually garrisoned or in a trench should be able to hold a specific part of the map until your MG arrives.
Once your MG arrives your third IS should be about produced upon which you can start back capping with both your IS and returning to assist the fight when needed.. However the backbone of this is the AEC, it helps snowball the game into victory and can get rid of the small caveat to this idea (mortars).
With that being said even without that tactic this is a solid build order anyway, and can be used in a different playstyle if need be. If your AEC's can't get rid of the mortars simply build 2 of your own which will counter his counter very effectively...
I can't really tell you where to go from the AEC but getting an AT gun would probably be a good idea and getting a mortar after that would be a great idea to solidfy your holdings... But I can't really predict further into the game what you should do..
An example of the general strategy
Semoisky: Bottom: The bottom creates less of a need as far as being assertive goes, given that you've a dominate position with the church. You'll want to have your 2nd IS cap the entire right side of the map (so you can fuel income and not be behind by that much resource wise) whilst your MG is sent to the building indicated near their cut off...
Essentially giving you dominace over the right side of the map. If this fails, fall back to the church and get your AEC's to repush. A few mortars would also help make you take their cutoff easily a bit later into the game.
Top: Getting the church would basically guarantee you the game here as it's so dominate when used against the top player, but it's unlikely given their proximity to it.
Nevertheless, if you manage to cap it and get an MG in there your have the center entirely.. However, you may not and in that event push the fight to the sides of the map till you can get adequate support (a mortar or two) up to push their inevitable MG out of there.
Authors Note: I was going to do some other maps, but've decided against it.
Whilst your learning experience may've not come to an end, this guide has. A small caveat to this strategy is that it requires a lot of micro to actually work as I am intending it too but, you'll get used to the playstyle overtime.
Another caveat is that whilst it's indeed meta it's not uncounterable. PShreks, tellars/schu's and 2 paks could counter this potentially which is where the first caveat regarding micro comes into play... If you play with your AEC's smartly they'll win you games through the sheer number of wipes (my last game was literally saved by getting 2 out and then wiping 3 volks w/ shreks and a sturmpioneer per example).