Ah, I see your frustration now. Those are the old North Face Hedgehodges I'm pretty sure. They were discontinued because the boa configuration on the heel side (rear facing) was problematic as you mentioned. It was too easy to bump it open. It works MUCH better when mounted on the tongue or the eyestay (like the shoe above).
ree, there is only one universal metric when it comes to shoe sizing between brands and that is the physical CM length on the shoe. Look up what DC shoes CM length is and then find the closest thing to it in 5.10's sizing. it is usually the last sizing scheme alongside Euro, Mondo and whatever else. That should do the trick.
Bums me out how much new stuff 5.10 keeps coming out with for clipless, while the flats line still resemble modified skate shoes. How about some Velcro straps or Boa system on the flat pedal stuff as well? I've went through three pairs of Shimano MT41's waiting for 5.10 to jump on board. I really don't care if they look normal off the bike. They are bike shoes. Make them functional.
I've been running a prototyped Boa system on my downhill shoes for the last two seasons with zero issues. Works great... especially in wet or muddy conditions where my laces used to get caked.