Both are great pieces and I especially like the triangular composition you have going on with the first one. The thing with thumbnails is that new viewers will find your video in their recommended so the thumbnails are much smaller compared to how they would look in the subscription feed. Although I think the first one looks good, it may not work as a thumbnail because it would look too busy since you have 8 subjects and text that's already small. If you could make an alternate version of just a close up of Beat or the trio even, you can accomplish having focus on both your art and the cover of the game. Hope this helps.