Could have been added later, but wood pole lights can't be at the same height or else the thru-bolts would get in the way of the opposing lights. The one on the right is an AEL 115 and the two on the left are M-250R2s. Looks like they need new lenses too.

Makes sense on not being lined up because of the bolts.
My guess was right on the M-250R2's LOL the AEL-115 I didn't know what it was. Will update the info section now

Yeah those lenses look pretty yellowed ....probably never happen though (unless they got cracked or something).

Here they'd replace the refractor upon relamping the fixture usually. In just about every cobrahead, to remove the refractor, you just rotate one clip and then you can take the refractor right out. In some you might need to loosen a screw to turn the clip. With the M-250R2 you just turn the tab 90 degrees and then you just lift the refractor from the "house side" and then it comes right out. When installing the refractor, you put the door on the light and have it hang in the open position and then place the refractor in the door's refractor catches on the "street side" of the door and then rotate the tab on the "house side" so that it goes over the rim of the refractor, preventing it from falling out. Older fixtures like some 60s fixtures and fixtures before the 60s, replacing refractors typically involved removing screws and often in those fixtures the screws either corroded or got stuck in place so a broken refractor would mean the whole door or the whole fixture would have to be replaced. Or a couple tabs coule be broken off or bent away so the new refractor can be put in.

Sounds like replacement is simple enough on the M-250R2

Just seems like I see allot of older apartment buildings around where the maintenance done is minimal
If along a roadway it'd probably get replaced...either that or the entire fixture 'upgraded'