Creating art for a digital card game that I am working on

Over the last year and a half I made a card game that I have turned into a physical prototype for the sake of testing. It is similar to Hearthstone in its core but brings new mechanics and innovation to their model. I have contracted 6 different artists in the past to do art so that I can identify the style for the game. What I need now is to make a digital prototype. To do this I would to create art for about 250 cards in the 6000x8000 px format which will be used for the game. I am looking for someone who could generate these images relatively quickly using AI generating tools (such as Dall-E, Midjourney or any superior one) with some touch ups. These would be game ready assets that I would include into the game. Alternatively, the idea i am playing with is creating just sketches and having one or couple of key elements of the image colored so that it could present a unique style. However, producing 250 cards by hand using this technique I hope can be done within a year. The workflow would presume that I explain the world, the setting and for each card provide a couple of descriptive sentences and I would look to find some images as references (depending on my free time but I will look to provide a reference for all of the 250 images I'd look to commission). I have attached examples of work of artists themselves. The setting is a Medieval high fantasy based on stories I am writing in my spare time. Respectfully, Slobodan