In my unmodded Julii campaign, Brutii did make the jump to Appolonia before 266 BC and expanded after that becoming very strong by 215 BC, but Scipii only took Sicily. I made the change to Scipii to prefer naval invasions, and reloaded my 255 BC savegame. Scipii has already captured all of Sicily in 255 BC, has two ships with 3 units of troops on one of them, and two nearly full armies at Capua. For 5 turns, the ships went back and forth alternately between Messina and Capua, but the troops were never unloaded I suppose because they weren't needed on Sicily. After 5 turns a Macedonian ship passed through the area, and the Scipii ships stopped moving after that for the next 5 turns which brought the game to 250 BC where I stopped testing.