There won't be any stronger climbers unless maybe Quintana. Contador will be past peak after the Giro and shouldn't be too hard to handle. That was it all. At least hypothetical.
The question is whether Froome will struggle in the first week. Actually he never has any real bad day if he peaks for a grand tour. He's very wise at pacing himself to avoid losing big time. Especially Valverde missed that ability in many grand tours he lost.
Rolland will cause trouble anyway. And Froome isn't a typical Sky rider anyway. He always attacks. If he has the legs to prove a point and if he hasn't just on principle.
The Vuelta could be easier to win for Froome. Arrive in good-shape at the first week, peak to distance his main-rivals in Andorra, pacing himself to avoid losing minutes afterwards, take back some lost seconds at the time trial, use the team to control the descend stages.