4 wine glasses per table setting?

See here

I think it's water glass, champagne flute, red wine glass, and white wine glass. I think two wine glasses is totally unnecessary and a waste of glassware.

One for red wine, one for white? Plus your already mentioned flute and goblet.

Red, white, champagne, water. I worked at a convention centre and this was pretty standard when we were doing banquets. Not really necessary depending on how your bar is run - we just had water glasses at the table and all the others at the bar because we didn't have servers pouring wine at the table, guests went to the bar for drinks.

Yup Kiwi basically broke it down.

The reason red wine (even going further with different types of red wine) and white have different size and shape glasses (and honestly the reason there are so many different types and shapes of glasses) is because they need more room to aerate and the way they are bowed makes the wine hit your palate in a different place, highlighting different flavors in each wine. It's pretty cool actually. If you have different glasses at home, try drinking the same wine out of a few different glasses and it will taste like a different wine.