Hi Mark,
I'm sure someone more knowledgeable will be along in a bit, so take all this with a pinch of salt but thought you may find it helpful...
Foods vary and it's trial and error I'm afraid but you'll end up being an expert on dog poo
Each dog is unique and feeding amounts will vary, but 200g for a 12kg dog seems a lot to me as does 5 poos per hour! Jack is 4 yo and 18kg which is on the high side for a Cocker, but he's always been a biggish boy. He's fit and healthy and not overweight. He gets 150g of Eden per day and usually does one well formed poo per day, occasionally another one in the evening. I used to give him 180g (recommended for his weight) but found he put some weight on, so have cut it back a bit for the time being (and cut out the biscuits!). Eden recommend 130g for a 12kg dog.
I'm tempted to suggest a change of food, just to see if it makes a difference. You don't have to buy a 12kg sack. I've tried Jack on Millie's Wolfheart, Acana and currently Eden. He's done really well on all of them, but I'm happy to stick with Eden at the mo'.
Edit: Have a look here for more info:
https://www.allaboutdogfood.co.uk/