Muhammad bin Fudail from Ashath from al-Hakam bin Utaiba who said: ‘When the people fled from the Prophet [s] at the day of Hunayn, the Prophet [s] used to say: ‘I am the Prophet no doubt * I am the son of Abdulmutalib.’
No one remained with Him except four: Three from Bani Hashim and a man: Ali bin Abi Talib, Abbas and they were in front of him, Abu Sufyan bin al-Harith holding the rein and Ibn Masud on his left side.’ (al-Musnaf by Ibn Abi Shayba, Volume 8 page 553)
Yes u r correct, Abu Sufyan ibn al-Harith ibn Abdul Muttalib was one of the remaining sahabis with the Prophet (saww).
You said according to Shia only 3 sahaba remained Muslim after the prophet?! where on earth (internet?) are you getting this information from?