Prior to the patch, there where ZERO farmable NPC's on alpha; they were either missing or bugged. So in that since, this patch has improved alpha ratting 100%.
According to what you wrote, I think you have not been very long in the alpha island.
Before the patch:
For each "alpha 2" island there is one fixed spawn with 5th star (mixed, from light to heavy) robots.
Moreover, (I know exactly just for Tellesis) there are another 5 spawn with 3rd or 4th star (mixed, from light to heavy) robots.
Sometimes (though rarely) appeared wandering spawn with industrial robots, Scarab and other their escort.
After the patch:
On the Tellesis island, there is only one 4th star mech and only one 4th star assault static spawn.
There are 3 more static spawn with 3rd star mech (2 spawn is green, 1 is blue).
All the rest are mostly light and assault mission hubs.
I met wandering spawn with 4th star mech with Scarab and other accompaniment, but here is an old problem that some of these robots are often stuck in the structures or in the sea, and after everyone else is destroyed, does not appear a new spawn, until you destroy the remaining jammed robot.
From these numbers, I do not see any improvement alpha ratting.