The Alien from Alien 3 may have been a slight bit taller when stood fully upright. The digitigrade legs would give him a bit more height, and might make him a bit taller than a predator, given that a standard, humanoid alien is about the same size as a predator.
i doubt by that time of the movie they discussed the height of alien 3 specifically.
Andrews: Let me see if I have this correct, Lieutenant - it's an 8-foot creature of some kind with acid for blood, and it arrived on your spaceship. It kills on sight, and is generally unpleasant. And of course, you expect me accept all this on your word
but they never saw him walking. by then. Ripley must have spoken about her previous experience. A1 is not 8 feet because a) he was seen in same corridors with humans and against humans, so he was as high as an actual character in an actual suit. it must be Bolaji's height plus a bit of an alien head (a bit because Bolaji had his head inside alien's head, not inside his neck, like later suits) and heels.
approximately same height additions go for a predator ("shoes" and head. head is significantly higher in P2 due to a different shape)
KPH was slightly higher than BB, so, despite the heels, creatures are either similar or predator is higher. that's what goes for actual measures, also shown against human characters in movies.
i haven't met anything about aliens supposed height in A2. but, as they are rarely seen against humans, never standing against each other, i cannot say that their head-to-body proportions, similar to A1, prove anything. if we consider them 8 feet, we must also accept that they are more massive than A1 - and ignore all shots in the movie where they are obviously the same. that's the only way to consider them 8 feet, as suggested in A3 (and not about A3) - and thus higher than classic predator height.
but in this case (now i return to the question asked about Neca proportions) all A2s should be higher than A1. based on nothing. but if this case is accepted, Neca proportions between alien and predator is approximately correct.
then there will be a question of undersized predators who don't go in scale with Dutch
