Please don't bite my head off, I'm only offering an opinion, and it may be wrong but...
Inbounds to BB/BE/NX, in a perfect world, would all route up the eastern side of the DTY CTA, purely because that's the way the traffic flows are organised, N bound on the E, S bound on the W, so routeing OCK HEMEL WELIN is for the majority.
Now for this route to work you have to be FL180+ or lots of other people get involved. So there's a get out for those who can't, or say they can't make FL180, which is SAM CPT WCO HON/DTY. If you're in a jet which can make FL180+ you should be going up the east side, and if you just happen to be lower then it's a case of see what's coming and can we get you up the WCO side. (Generally not cos the WCO side usually resembles an avalanche of a/c heading to the TMA or out of BB etc going south, and you'd be going head on to them all!)