Dave, have to respectfully disagree with you about the XP-72. Yes, heck of an aircraft, but... Probably the best prop fighter to get to a War Zone but not see combat, and was made in large numbers (555) was the P-51H. It could do everything the 72 could do which was more than a match for anything else already out there short of the Me-262, was already in production, used far less resources to make and use, fuel efficient, MPG on the XP-72, ouch!, was a lot less complex and far more maintainable and I'm sure a lot less expensive over all. The Merlin was a Mature engine, the R-4360 was not. My Dad told me they had problems with the Corncob from his times at American Overseas Airlines, after WW2, with the first batch of Stratocruisers' and these engines were being operated to Civilian standards, not in a War Zone in Combat. Heck, SAC had problems with them in the '50's with the B-36. How many times I have been told by former B-36 crewmen it was totally not unusual to take off with 6 running and return with only 5, sometimes 4, still running. I know, unusual backwards installation etc, but still, in a single engine Fighter a Decade earlier in Combat, no thanks!
About the DO-335. I am a Native of Alexandria VA. I have been going to the Air and Space Museums since I could walk, early '60's back when I could barely reach out and touch Yeagers' Bell X-1 sitting on the ground, to Silver Hill, the NASM DC and U/H on literally hundreds of times. My point, I'm now 6'9" and have literally grown up around all of these aircraft all my life and the DO-335 is still Freaking HUGE compared, to me, to any other fighter, P-47 included. It's like F-4 Phantom size! My Dads' opinion on the 335 besides having 2 engines on a fighter was from a maintenance side was simple. The higher up off the ground, the harder and more time consuming it is to work on. He absolutely hated the DC-10, I remember the first one we saw together when I was young. He pointed to the tail mounted engine and asked me, "what's wrong here? ". I said I didn't know. He asked, how do you get to that engine without a lot of new and expensive equipment unique to this plane! In my Decades of flying on A/A, I was forbidden to fly on one and I didn't disagree.