Launchberry is a major one, though somewhat understandable with Kruis and Itoje there. Still, I'd have had him and either Gray brother in there ahead of AWJ and Henderson (twice outclassed by opposing locks in the 6N, though admittedly a brilliant young player).
Ken Owens is a very good hooker but Rory Best is an inconsistent thrower like Jamie George who has never started a test, so Fraser Brown and Dylan Hartley may feel hard done by. Given George's destructive qualities in the loose are arguably greater than those of Best, I'd take the former along with the versatile former 7 that is Fraser Brown.
Biggar has flattered to deceive for Wales for the past year in a faulty midfield. Finn Russel and Paddy Jackson offer better options.
Jared Payne simply isn't a world class full back or centre, so I'd take Duncan Taylor who is recognised as the most consistent all round centre in the Premiership and is similarly able to play 15, given that two wings also play 15 (Watson and Williams) and Hogg is nailed on to start. Whilst the Taylor's hopes were seen as being dashed by injury during the 6N, Payne was also injured so it's a moot point in that context.
Jonathon Davies is also in poor form, so pick from Gary Ringrose as a bolter, Alex Dunbar as Mr Consistent or for me, Scott Williams as the better Welshman.
Leigh Halfpenny's kicking isn't needed given Sexton and Farrell's proficiency, so Simon Zebo, already a Lion, has to be in there, again offering wing cover as well.
I imagine Sean O'Brien is there as a midweek captaincy candidate, but Hamish Watson is the more natural and energetic 7 to disrupt the opposition. Toby Falatau is lucky to get in ahead of the versatile (6,7,8) Barclay when the Lions already have Stander, Moriarty and Vunipola able to play there.