Bottom right is definitely the latest as its a stereotypical looking Spanish Conquistador, armed with a musket in his right hand, and thus near the end of the use of armor by Europeans, most likely in the early 1500's. Wearing a combination of basically what all three of the Conquistadors depicted here. Even this idea of fairly well armored men seems to be more a modern invention, with very few men on even Cortez's early expedition having chain mail much less plate .

The leftmost figure of the first set appears to be some mish-mash from the classical era. He's wearing a pseudo-corinthian helmet, not a commonly worn, any representations have been on Roman Republican officers.

He's got a either a linen (worn by the Greeks) or mail cuirass (worn by the Gauls or Romans) and the pteruges which suggest Roman.

The sword could represent a gladius which suggests Roman but the shield could be a light infantry shield - certainly not a heavy infantry one (and officers don't carry one).

The second one is the strangest: I say, he is wearing plate armour, because of the prominent besagewes to protect the armpit, plus greaves and vambraces and then ... A curved nasal helmet.

Those two things just don't go together. The armor looks like from the 1400s, while the helm looks no younger then 1100. The weapon seams to be meant to be a mace but the sculpturer could not do thin objects. - That does not help to narrow it down.

And finally the shield ... center grip round shield like a viking shield but I have never seen a shield boss like that and it's smaller and with a metal rim but not all the way a buckler.

I go with "A northern german knight from 1400, wearing his great-great-grandfather's helmet."