OP, I don't think your names are weird at all! Great, solid old names. I also would need to be corrected as to Cassius' pronunciation, but that's OK.
I have to say that the only name I have (slight) regrets over is the really mainstream one we picked. He was going to be Lachlan, but we didn't think he looked like a Lachlan after he was born, plus we couldn't settle on a nickname. So, after several days of dithering we named him Jonathan for my Dad (Cyrus mn for DH's grandfather).
My oldest is Tristan, which showed up on that recent hated list, I suspect because that dumb movie came out the year after his birth and now there are Tristans popping up like weeds. We named him because I loved, loved, loved the BBC's All Creatures Great and Small when I was a child. Plus the chap who sold us our engagement ring in London was Tristan...we really liked him, and he was thrilled when we showed up for a cleaning a couple of years later with a little Tristan in tow. I have to correct people all the time....they think he is Christian. No problem, though, it only takes a second to do.
DS3 is named Peregrine, and that always gets a response, either really enthusiastic or 'oh, that's unusual', which is code for 'you are an insane, cruel mother'. I am disappointed to find that some few girls in the US are being named Peregrine, but that is my bias....I loathe boy names being co-opted by girls. No one has been outright rude, and those who seem uncomfortable settle quite happily to calling him Perry. His mn is William, should he ever wish to go by a more conventional name.
I think you will be just fine with either name, OP. Congratulations!