Hi, remember last L&B? The shades were very very close, but a bit different? Well to some they were and to some they were the same. Tom Ford will often change something very slight and re promote it. Example Beau was Blush Nude. The summer duo shadows, the creams were close, but a bit off. I think some of the lips are almost dupes!
My advice is look for the shade you like , then decide if you want it in a larger size or a smaller one or like the junkies we are, in both!
As for Estee Lauder owning, yes the same factories and production are producing Mac, EL, clinique , TF. The formulas are different though.
Example, I used to work for PX! I loved magic powder, they changed it a bit when PX was taken out of stores and added it to the MAC line up.
A company will use the same ingredients, but not the same formula. I feel TF formula is superior to other Lauder brands.