Are my changes to the Warak’aq too broken?

[xXEndG4meXx]

I’m making a mod that will add some things to the Incas. For now, the section I’m interested in is this one, and I’m not really sure whether the unit would be OP with the proposed changes.
If that’s not the case, would it be fine to allow all units to always ignore the cost of hills?

LEADER UNIQUE ABILITY: QHAPAQ ÑAN
– In addition to the previous bonuses, I added that all units ignore hills if they are in owned territory or adjacent to it.

CIVILIZATION UNIQUE UNIT: WARAK'AQ

• It now replaces the Archer (its stats are changed to match the Archer’s).
• It has 3 movement and costs 40 production (the Archer costs 60).
• Range = 2.
• It can attack after moving if you are on a hill.
• You can now attack twice only if you are on hills.