Disagreed and agreed.
The important factor to look at on any aircraft isn't it's Maximum Speed, but it's Cruise Speed. To make it more complicated, there's also Long Range Speed and Endurance Speed, but let's stick with "Cruise Speed" for a moment. For jet aircraft, that's also a bit deceptive since turbojet powered aircraft cruise faster the higher they go. Sure, there's a limit on that altitude, but in general, it's between 30,000' and 50,000'. Agreed max speed is unsustainable due to fuel consumption.
That said, a fighter, which has a higher thrust-to-weight ratio than a tanker, is going to cruise faster. If you put the same motor in a cement truck and sports car, are you really going to believe both will go the same speed at the same RPM?
F-22 Raptor > U.S. Air Force > Fact Sheet Display
KC-10 Extender > U.S. Air Force > Fact Sheet Display
Your fact checker is a bit off. The KC-10 can maintain 500 kts. Your picture also shows the F-16s flying in formation which is normal. Just because the F-22 can supercruise at mach 1.3 doesn't mean it will be doing it all the time. That is it's Max supercruise. To keep it from gulping fuel, it will be closer to 500kts for max range with the Tanker.
Funny you should mention the cement mixer and sports car. At 500 kts, the tanker is much more economical than the fighter. His engines are trimmed for subsonic and transonic flight while the fighter is trimmed for supersonic speeds. Both have completely different engines built for a specific speed. Even so, if you try and fly supersonic, your range is shortened by a large margin including the F-22.
There was a report published in Avleak a few years ago that reported a useful supercruise range of 400nm.
IOWs, it has to fly subsonic to cross the pond and at 500kts, the speed of the tanker is about equal. The last fighter that could fly across the Atlantic was the P-38 with drop tanks. Its still over 3000 miles.
The P-51 could do it too. In fact the P-51 held the transatlantic speed record, both ways, for at least a year.
Only one held that record and it wasn't a military bird. It was a very highly modified P-51C Racer with the entire wings modified to hold fuel.
North American P-51C, "Excalibur III"
Yes, but regular P-51's crossed from the USA to England during the war on a frequent basis with just normal drop tanks. They weren't trying for a speed record. Some stopped in Greenland, but more than a few did the whole distance.