Training grounds has been around forever. How about spicing it up and letting coalition members share decks that others in the coalition can test-drive? It would make the Training Grounds feel like a place for testing new things, and give players a peek at cards they may want. (Driving more purchases) 
Actually thereās a game āHorus Heresy: Legionsā that Iāve been turned on to and there you can actually share at least what your deck looks like with others in your āCoalitionā (Lodge, there, but whatever).
It would be cool if you could click on your mates and see decks not the āFavoritesā but ones only to share with your Coalition (so not everyone got to see your deck ideas).