I take GaramondPremrPro for example.
The glyph of the / I / has: LB 35 and RB 26; the kerning added for the pair / II / is 9pt, so it is symmetrical: 35pt distance between the two serif close together at the bottom.
The glyph of the / E / has: LB 19 and RB 23. The pair / IE / has 9pt of kerning: in this case the two serif close together at the bottom are 54 pt apart.
The glyph of the / A / has: LB 4 and RB 1. The pair / AA / has 10pt of kerning, so that the two close serif below are only 15pt apart.
Are these different distances normal?
At least the couples / II / and / IE / shouldn't be equidistant?
In any font family, one of the first things I do is establish a standard height (usually about halfway up the x-height) at which I make all spacing measurements. This is key to being able to systematise spacing.
(I assisted with the production of Garamond Premier Pro. Robert Slimbach once asked me to take a pass on kerning a particular font. When I came back with my work, he basically told me it was all wrong and re-did it himself! He saw it all differently than I did.)
It’s tempting to make the sidebearings of a glyph like A equal -- and there’s a decent chance that looks good -- but a serif A probably has a thin stroke and a thick stroke on the left and right, and that might have an uneven optical effect. Again, always use your eye and don’t trust the numbers.