U might get a little bit more coins on squad battle since you're playing harder opponent so the skill multiplier is slightly higher. You also get a good amount with ur reward depending on where you finish. But in the end, u gotta grind to get coins.
Get urself the coins boost from EA catalogue (R3 on PS4). Don't use coins to buy pack, use coins to buy players depend on market. Use players to complete the SBC, which will award u pack that usually end up being cheaper than buying packs.
I don't spend money on FUT so it takes longer to get a decent team and you really got to get involve with trading to make more coins.