They’re going to be on the taller side.
I think the Viera will follow the same dimorphism rule that most of the other races in the game do: males are generally taller than females. The only exceptions to this rule are Lalafell (males and females are the same height) and Au Ra (males are significantly larger than females).
If Viera were to be an exception, then what I can see happening is males being the same height as females (like the Lalafell example). This could be explained by their lore of how males and females are indistinguishable at very young ages.
Either way, I highly doubt they made them the same size as male Miqo’te or even male Midlander. Male Viera height being close to male Miqo’te height would make them too similar. Male Viera should stand out from male Miqo’te the way female Viera stand out from female Miqo’te.
If anything, a minimum male Viera will probably be about 2-3 inches taller than a maximum height male Midlander. There would still be a noticeable difference between minimum height Viera and maximum height Miqo’te (this is true for the females).
A maximum height male Viera would be taller than a maximum height female Viera, but a minimum height male Viera would be shorter than a maximum height female. That would be totally normal, as this is possible with other races (minimum male Elezen < maximum female Elezen, etc.).
This is my prediction for their height.
And this is how the female Viera currently scale in-game.
