I hope you're happy, I spent 20 minutes gathering data to prove this post false.

(Most numbers Media Create, used 2 sets of famitsu numbers when I couldn't find MC numbers)

Persona 3: 210319 (Famitsu)

Persona 3 FES: 165471 (Famitsu)

P3: FES (Best): 20043 (MC)

Persona 3 Portable: 232344 (MC)

P3P Best: 109,832 (MC)

Persona 3 + FES Total = 395,833

P3P total = 342,176

Difference = 53,657

Persona 4: 335,839 (MC)

P4 Best: 96,038 (MC)

Persona 4 Golden: 232,639 (MC)

P4 Total = 431,877

P4G = 232,639

Difference = 199,236

So no, P4G didn't nearly sell more relatively or even absolutely (yet) more than P3P.