The big gold boosts and discounted production is very strong if you're lucky enough to get the card combo. This isn't OP because each spot has a production limit based on your gold, so your home territory can only ever produce 8 units. I've definitely popped out 8 juggernauts in one go on a few occasions. It's just the way the cards flop.
As I've said before, using 250% gold card will increase the income capacity of the capital to 20. Increasing your production queue to 20 since unit production is dependent on how much the country is earning.
Yes, it is dependent on luck, and utilizing your resources well, so it might have been intentional on the part of the developers hence the question mark above.
On the bugged screenie, I'm actually the defender. There are no entrenchments. I don't even know how to produce entrenchments. The AI is attacking that country always. Sending out one unit at a time. Big reason is to immobilize my troops inside and hinder any troops going in.