if it helps, after agonising over the same question last year I found it really helpful to look past the 2 obvious factors (handlebars, tyre width capacities) and focus on the real differences that would make a difference to how I hoped to use the bike.
Those differences can be found in looking carefully at each component selected by the designers for each bike. One bike gets you into pretty high end rims, hubs, chain set and expensive “Brifter” territory with associated cables and goodies that should all stay together for a long journey from home and travel at a decent pace with gearing to allow for most challenges of contour. The other has more clearance between its larger tyres and brakes with the handlebars to support riding unmade roads. Has the gearing for dealing with ups and downs too with the associated controls to suit.
Wanting drops with indexed shifting is a major factor in your decision between the two bikes by the look of things but it means giving up on the hub gearing.