Since I mentioned Ike and Lukas, let's do a few more. All characters listed I have in-game, minus a few

Reinhardt, Legion, Seth

Soren and Alm

Matthew, Jakob and Saizo (hey look, all dagger users)

Roy/Lillina and Alfonse/Sharena

Fae, Kagero, Nino

Karel, Raven and Henry

Abel, Jeorge, Laslow

Sakura, Bride!Charlotte, Ninian and Est

Oboro, Shanna, Effie (Chrom's VA made a joke about this on his twitter)

Michalis and Robin (M)

Lucina and Palla (uncredited)

Clarisse and Julia

Female Robin, Summer Robin and Sheena

Summer Leo and Gordin

Nowi and Clarine

Odin, Narcian  and Lloyd

And for our final one for today

Python has the same VA as T.K. from Digimon 02. I know it isn't Heroes but I wanted to mention that and the fact of Veronica having the same VA as Patamon.