Unless you can prove that a 500 with a 1.4 16V 99bhp 97lb ft engine and a Panda 100HP with same said engine and same said power figures has different maps, then best not to state such things as its conjecture, and looks silly as different maps to achieve the same results doesn't add up and would be a waste of manufacturer development money when an existing map exists.
Have a look at this quote from a tuner on here from a previous thread
I have seen both in the flesh and the funny thing is that despite being on the same platform and the same engine there is a difference in the ECU's. The new 500 ECU we can map easily, but the Panda 100 creates still a lot of problems.
https://www.fiatforum.com/panda-new/124032-panda-100hp-better-than-fiat-500-1-4-a.html
(Post number 3)
As above, both the Panda and the 500 have the same engine but different ECU's