Tsetserleg actually has quite a low blood percentage (47%), but of course has a significant amount of 5* experience and hasn’t had issues with fitness over tracks at that level. The same can be said for Mai Baum (31%) and Off the Record (40%).
Leamore Master Plan and Vermiculus have very high blood percentages (80% and 100% respectively) and have galloped around the biggest tracks in the world (both have jumped clear around Burghley, LMP has also jumped clear around Badminton). Vermiculus might not have the fastest turn of foot, but I’ve never seen him tired.
I do believe they picked the right team for this track. They picked true five star cross country horses, with an incredible depth of experience. WEG will be big, and Giuseppe will be clever and use every tool in his box, but it is still technically a four star cross country test. If this team fails, it will not be because they were not up to the challenge.