Let’s look at the worst case on a BA rival flying a 777: it’s 7 across with four seats having direct aisle access. That makes 57% aisle access. The best case is Qatar with 6 across, of which four have direct aisle access (67%). Any carrier flying an A330 or A340 offers 67% too. BA, by contrast, has 8 across and four have direct aisle access (as VK points out, 50%). It sounds like a competitive disadvantage to me.