Well, I did the math and a 400 gr arrow at 290 is 74.71 pounds of KE. A 550 gr arrow flying at 220 is 59.12 pounds of KE. That's not opinion, it's fact.
You are absolutely correct with these numbers. However unless you change something else in addition to the increase in arrow weight a bow that shoots a 400 gr arrow at 290 ft/sec will not shoot a 500 gr arrow at 220 ft/sec but rather 255.8 ft/sec using 125 grains virtual mass . That is a KE of 79.9 ft lbs.I don't know where you got the 220 ft/sec but it is incorrect.