FWIW, in Salomon's Quest boots, a size 10 (EU 43) works well for me (maybe just a hair longer than would be perfect). The size 9.5 (EU 42.5) in the Aeq Hike is definitely too short for me, to a greater degree than I would expect from a half-size difference. So I think a 12 (EU 45.5) would be the safest bet to try on in your case.
As for that size chart suggesting two sizes for the same foot length, the chart is probably for ski boots. For those, the shell of the boot is the same length for a 45 and 45.5, 42 and 42.5, etc.