It is a coherent choice to maximize liquidity
Prosperous Innkeeper sets itself apart by refunding some mana in the form of a Treasure token
And with access to all the colors, we get to run broken things like Dockside Extortionist and Smothering Tithe
Meanwhile, Spectrier and Glastrier do appear on more cards than one, but Calyrex takes the reins with its fusion, leaving these noble horses to freeze and fade away without their own spotlight
The official Japanese Pokemon Card Game card-search interface lists AR and SR as separate rarity filters, which is useful when checking card identities after arrival
Expansion and Field of the dead are our more traditional ramp payoffs, with the former just burning someone for a large amount as well as giving us a ton of cards, and the latter just making zombies everywhere for us to eventually overrun the opponent