I'd say they were able to, and that they did; SNES beat the Megadrive 49 million to 29.5 million, so by over 60% more consoles sold. (http://www.vgchartz.com/analysis/platform_totals/)
And Nintendo didn't have "all the advantages" either; Megadrive had a headstart which they fully capitalized on by advertising how much more capable their system was over the ageing NES. The Megadrive was certainly not a weak opponent; Sega were at the top of their game in the late 80s and early 90s, don't let their dismal performance later on fool you as to how formidable they were in their prime.
I don't think sega was a pushover. But that they were ahead of SNES until they lost focus. Which just shows that Sony coming more structured than Sega they would likely oversell N64. Still SNES was stronger, more well know, with more partners, and momentum from NES. They had much more advantages than they would against PS1.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"