I agree with that. Maybe add Matt Fagerson too for sheer consistency.
6 is probably the least clear cut position for the Lions IMO.
Previously, Lawes and O'Mahony would probably have been favourites but Father Time has changed the picture and I don't think there's a really obvious choice. I thought CCS might be a bolter for that shirt but he's had a bit of a dip in form and isn't guaranteed to make England's starting XV right now.
Maybe Lawes and/or O'Mahony still make it? If not, I think it's between Fagerson, Chessum and CCS. Maybe Tom Curry if he's considered a 6.5 type?
As far as a combined XV's concerned. Scotland would have more right now but lots of close calls:
1. Schoeman
2. George (Turner)
3. Z. Fagerson
4. Itoje
5. Martin
6. M. Fagerson (CCS / Chessum)
7. Darge (Underhill / Curry)
8. Earl
9. Mitchell
10. Russell
11. van der Merwe
12. Tuipolotu
13. Jones (Slade / Lawrence)
14. Feyi Waboso (Graham)
15. Kinghorn (Furbank)
I'm basing that largely on form though and I put the most debatable calls in brackets. For example, I think Darge is in better form at this moment in time, but both Underhill and Curry at their best are better players.
I wanted to go for Willis at 8 but until we can conclusively say his domestic and European form translates to test rugby, it wouldn't be fair to include him in a combined XV.
In other areas, combinations come in to consideration. I don't necessarily think Huw Jones is notably better than Slade or Lawrence but he's definitely been in better form and has a great partnership with Tuipolotu.