il give you a example of all the reason why each of them would not be rated EF5 today...
note... what im about to say is using the logic of NWS 2014+ and a lot of this was said with villonia in particular
- greensburg: trees standing within 50 yards and debris from all the homes touched the EF5 damage thus EF4
- elie: no scouring and one F5 Di , trees standing close by thus F4 (old scale and canada but i put it here since its post 2000)
- Parkersburg: 2 homes rated EF5 since they were alone and had major debris granulation no trees standing within 100 yards, and some ground scouring nearby thus EF5. (however all other areas were hit by debris thus the main parkersburg area has no EF5 rated area)
- Philadelphia: trees still standing close by and no true EF5 di found, thus EF4.
- Smithville: trees standing within 50 yards , most of the buildings were hit by debris form other homes thus EF4.
- Phil campbell: homes were hit by debris nearby for most areas, small shrubs and bushes are fine beside the so call EF5 damage, no ground scouring in most areas and trees standing close by ... thus EF4 (note tim marshall wanted this one to only be rated EF4)
- Rainsville: homes hit by debris in some areas , trees standing within 30 yards away thus EF4.
- Joplin: trees standing within 100 yards in some spots... every home were hit by debris thus EF4.
- el reno 2011: only one good area that could be found as EF5 damage... however not a official di and we can not rate a tornado EF5 base on one di... thus... EF4...
- Moore 2013: trees standing within 100 yards away.... homes all hit by debris , only EF0 damage beside some of the EF5 damage... thus EF4.. (home home did not suffer from debris impact however had trees standing close by)
so ya .. thats why likely most of them would not be rated EF5.... sadly...
oh and just to be sure before anyone says villonia and mayfeild had one tiny flaw in the construction ... that isnt the point .. the point is they mostly had to use debris impact... trees standing 100 yards .... and cant rate this ef5 cause one di only.... if its poor quality... then so be it... but they had no reason to bring up trees far away or only one EF5 damage point....