That hole position does look odd compared to what I am used to but EV made the speaker to be used that way, so it must be 'safe'. However, its probably a bit like the QSC pole height issue. QSC put into their literature not to use certain tops with certain pole lengths due to instability- especially when using K subs.
I could see these EV tops being fine with 18" chunky subs.
Well, I own Yamaha DXR10's and I LOVE them. Disclaimer - I have only used them as monitors but the sound quality sounds good to me - no suck out -in that mid region. I prefer my DSR112's for exactly that reason BUT I realize you only want 10's. i think the DXR would be a good option for you.
Think QSC K10 (mk1) but much better - richer, warmer, louder IMHO.
