I kind of have to agree with this sentiment; the "black prince" tank really doesn't fit in the game, and opens up a lot of really strange things to be added.
Wikipedia claims that there were 6 prototypes built, with the earliest completed in May 1945; definitely after the Italian campaign, and also just after the end of the war. The problem is, historically, the project was cancelled because of the success of the Centurion tank, which again according to wiki:
Six prototypes arrived in Belgium less than a month after the war in Europe ended in May 1945
That's quite a coincidence; the same number of prototypes built, completion within the same month, and even being shipped to Belgium (which is further than the BP got). So does that mean the Centurion is a valid tank to add? I wouldn't say so - it was
far better than any other WW2-era tank (that served, anyway), and continued to serve until 1972, at which point every vehicle in the game was severely outdated.
Then there's other tanks as well, that existed to some degree or another:
- Maus (2 prototypes in 1944)
- possibly the E-100 (incomplete chassis in 1944)
- the Panther F (several turrets made in 1944, none tanks actually completed)
- IS-3 (reportedly saw combat, was present in the Sept '45 victory parade)
- possibly the T28/T95 heavy TD (aug '45 might be too late)
- possibly the Tortoise A39 (post-war, '45)
etc....
My preference would be to stick with vehicles that existed and saw combat, even if they were incredibly rare.