Kevin Peter Hall (Predator): 7 ft 2 in (218 cm) (wikipedia)
suit additions: artifitial feet (same as alien), head crown & helmet add a little to actor's head (in P1. in P2 his crown was a lot higher due to another head shape).
Bolaji Badejo: 6' 10" (2,08 m) (imdb)
suit additions: artifitial feet (same as predator), head adds just a little to actor's height (same as in P1):
so even if suit additions are similar in P1, alien is still a little lower.
if compared to P2, alien is a lot lower, but this Neca set uses P1 body.
(i specially take only A1 as an example, because all others didn't have giants playing them, but it was not intentional)
as i said, actor Hall was higher than actor Badejo. you can google their artificial feet and see that they were similar.
so their waists and eyes should be at least on one level. (Bolaji's eyes are somewhere in the middle of alien head, unlike A2 and later, where actors stored their heads in fat necks).
here predator's waist doesn't even reach the beginning of alien's body, and predator's eyes don't even see alien's neck.
so no, Neca scale is so wrong that even ht didn't get it so wrong (unless you take into consideration their midget P1).
to be in scale they should be like this: