[Ma4b2] Isomerism in coordinate complexes cofusion

[nishantve1]

Consider a complex with Central Metal atom M
A and B are monodentate ligands .

Consider a compound with formula as
[M A₄ B₂] . Textbook and the web says there can be only 2 possible isomers of this compound .

What I say is, why can't I in the first image put A on the top and bring B towards the bottom something like this

.
And them form these,

That will give a total of 2 new ones I formed and the two old ones, 4 isomers .
Why is this not possible, I mean why can't a occupy the two places ?

 

[Borek]

Are you sure the molecule you get after switching ligands is different from both original ones?

 

[nishantve1]

Bummer! should've had checked once, yea they are the same.