Cornerstone versus Oliver Wyman

Deciding between offers with OW and Cornerstone and unsure of which to pursue. I'd really appreciate any input on graduate school opportunities for MBA or PhD programs in Economics.

I think I'd enjoy the broader business problems at OW, but the economic theory at Cornerstone in the daily work. I'd say I'm leaning towards OW but am mainly hesitating because I'm unsure if the grad school opps are equal between the two firms. I'd be potentially interested in a PhD after a few years at OW but don't know if that's feasible/if Cornerstone would set me up better for that.

Ideally though, I wouldn't actually use the PhD in my career until significantly later and would love to explore CSR, impact investing, social business etc. for a significant period of time before doing research.

I'd love any input or advice on which firm might position myself better for graduate school & future social impact career opps.

Thanks!