Very cool Boros Deck! Reminds me a little of the standard Boros deck that was so powerful during Theros block. On that same note, some of the cards from there may
serve this deck really well.
Akroan Hoplite is a great aggressive creature who's at its best in creature heavy decks like this. The Boros god,
Iroas, God of Victory seems perfect too. He's about the same price as a
Hero of Bladehold, and could probably take one of their spots (to avoid messing with curve).
stepping away from theros,
Ride Down is great in creature heavy decks. Might be best as a sideboard card though to get past creature heavy matchups.
Waves of Aggression could be a great finisher for the deck. Getting to retrace every turn late in the game seems like autowin with creatures like
Hero of Bladehold and
Brimaz, King of Oreskos. Just something to think about.
I hope you found this helpful! Good luck and Happy Hunting