Maybe this'll help a bit, maybe not. At least it'll give a more...human dimension to these things, rather than just big blocks of buildings from afar.
Wikipedia's providing the heights, and none should include any pedestals they may be standing on.
Going by The Dreadnote's size chart, this guy's about the height of a warhound.
Note that their proportions are significantly different, as a Warhound has bigger shoulders than even Paul Bunyan!
So how about a revenant?
Note that the Vulcan statue is the largest cast iron statue in the world.
And even this next guy is only a meter taller than a revenant. Also note that this is about the height of the Mount Rushmore heads.
This seated Buddha is about as tall as a Reaver. He contains a museum.
Cristo
de la Concordia is the largest Jesus in the world (taller than Christ the Redeemer even). He is about the height of a Warlord.
Then comes the statue of liberty.
Then comes the Imperator, somewhere in between these statues.