Head to head
Which one will break you first?
Two fingerprints on one grid. Both are scored through your profile, so this answers the question for you rather than for the average player.
Dota 2 is the harder of the two for you, by 1.8 points. The gap is widest on obscurity, where Dota 2 asks considerably more than Age of Empires II: Definitive Edition. If you want the gentler run, start with Age of Empires II: Definitive Edition.
Axis by axis, biggest gap first
DOTA 2
Every hero is free and every one of them can do something no other game would let a hero do, which is why the learning curve is measured in years rather than hours.
The game is the antagonist. Good luck.
AGE OF EMPIRES II: DEFINITIVE EDITION
Build orders are the curve, and the campaigns teach almost none of what the game actually asks for. The hard AI does not forget its economy while it fights.
Sustained pressure. Progress is earned.