Please go back to the original question, which was about longitudinal dihedral. The explanation given was that as tail alpha was a lower value than wing alpha a gust increase would give a greater proportional increase in tail alpha. so far so good. The explanation then went on to asume that this longitudinal dihedral had produced an extra element of positive stability because LD had produced "greater" tail lift. This is not so. LD does not significantly affect longitudinal stablity, only the balance of forces in level flight. It may (Wikipedia) affect phugoid movement in pitch
It is the use of percentages that leads you astray. Consider the case where ths pre-gust position has zero tailplane alpha. Any increase in a gust would give the tailplane an infinite percentage increase alpha. That would bring the nose down with a snap!
In fact, the tailplane, like the wing, has received the same finite increase in positive alpha and this would be the same with or without LD. I suspect the real reason for LD is to minimise trim drag in the cruise