Did any of those guys play against Luka Garza? No, so they have no more personal knowledge of playing against Luka than I have.
If this were a disagreement over Luka being All Big Ten you'd have a better argument. But we are comparing a two time 1st Team AA, 2 time unanimous B!G PoY, possibly a national PoY, 2 time unanimous 1st Team All B!G, and the winner of half a dozen other national awards and the schools leading scorer. Roy has only the career leading scorer and none of those other accolades, and Luka even set the career record 15 games faster and with a much higher shooting percentage, even a better 3 point percentage. These are some pretty objective factors in comparing the on court careers.
When it comes to memory, recency is always better. Its actually known as the Glory Days effect. Everyone, as in almost every person on earth, tends to remember their glory days as superior to the present. Roy, Ed and BJ-and the rest of those guys, all seem better to other mid 50s guys who are remembering their own glory days as presenting tougher competition. That's like parents talking about walking 5 miles uphill in the snow to go to school.
I'm not "invalidating" their opinion, I'm disagreeing and offering the reasons that support my opinion, and those reasons are numerous vs. a handful of guys that are remembering events from more than 30 years ago. Those Clones can have their own opinions but their opinions are in opposition to not just my opinion but opinions and success metrics of almost the entire basketball world.