Pygmy grass Blues and Lesser grass Blues, whats the diff?

Lesser grass blues are so common that anyone could just
accidentally step on one flying around a grassy roadside.
They really like the nectar of the Common vernonia and
Coat-button flowers. However, there is another butterfly
that accompanies the lesser grass blue at the roadsides.
That, is the Pygmy grass blue. They look very similar and
are often mistaken for one another. There are some
differences, and that's what I'll be talking about.

Above, is a Lesser grass blue, and below this
description, is the Pygmy grass blue. You can tell a
lesser from a pygmy by the spots on their hindwings.
That, meaning the underside. A lesser's spots circle
around a slightly curved line. However, the circle isn't
quite neat. It is rather broken. With 6 on the left
of the line, 2 above and 4 on the left. The lowest of
the 4 on the right of the line is tiny and often not well
seen. For a pygmy, the spots around that curvy line
are in a nice circle. There are 13 spots in total, 1 spot
that is tiny. The pygmy is also slightly smaller.

An extra thing to look out for: on the forewing of the
pygmy grass blue there is a deeply down-curved
line that the lesser grass blue does not have. There is
one exception. The pale grass blue. It is larger than the
two and has a more pronounced wing boarder.
So the next time you find a grass blue, be sure to know what it is!

p.s. : photo on top is a lesser grass blue taking off.