Originally Posted by
phoneticduck
avoid going back into Tokyo and the associated faffing around....
TBH, there's not much faffing around - and you don't need to go "into" Tokyo really. Travelling via Shinkansen, one can alight at Shinagawa station and take the Keikyu line from there to HND.
As you correctly observed, HIJ is so far from downtown Hiroshima that the total journey times from Tokyo for planes and Nozomi trains barely differ.
(If you're using a JR pass, which isn't valid on Nozomi trains, it takes longer - not least because you typically have to change trains at Osaka).