No. Placing a Smart Order doesn't set any money aside. Your balance stays available while the order waits, so it can stay invested, and you can still trade or send it.
That means the money has to be there when the order triggers. If you don't have enough at that moment, the order won't go through, or will only partly go through.
If your balance is lower right after you place an order, the order isn't the cause unless it has already run. Your transaction history shows what moved.