I'd agree with the two. On Leona, you need the HP from the Sightstone. And as it actually can be considered a gold-per-time item. When I play Leona nowdays, I don't rly get a chance to actually build philosophers. Rushing Solari after sightstone might be a good idea aswell = you protect your adc from burst dmg through for example, a gank, and you get the hp which you need.
I'd prefer that over the start-items you have suggested.

Sightstone first, all the time.

-1 for Philo stone as first item on Leona. I usually don't nitpick on only one thing, but this pretty much shows how little you know about the support role in general - because it is a rather poor first item.