I would take 4 Leo A4s over 1 PT-91M any day
Also, according to Wiki, the A4s were produced between 1985 and 1992.
That makes them to be 23 years old at most.
Furthermore, if something could be done to acquire the Leos A4 from the German government for $.5 a piece, that would be a very good deal - but it would require an outside of a box thinking from the Polish Gov.
I would preferred to have a Mercedes from the 80s over the souped up/ modernized Lada 1500