You make it sound like all Mustangs are created equal when that is obviously not true. For the money it would take to get a lesser Mustang to a Terminators power level, you could have bought the better platform and still have a huge amount of room left to go faster. Lets also not forget that not everyones wallets are created equal either lol.
All Mustangs were created equal, they just had different stuff bolted into them.
I could start with a '96 V6 Mustang, swap in a 500 rwhp V8 (numerous paths to this), IRS, 03+ interior, etc. for cheaper than the $25,000 it would cost to buy your typcial used 03/04 Cobra.