Cant really compare account sizes between different types of traders.
For the majority of daytraders/scalpers out there, they arnt able to generate the same returns with say a 1 milion dollar account as they are with a 100k account due to liquidity, esp if your lookign for only a few ticks at a time. Upper limit for most scalpers accounts i would put at 100-150k per index simply due spread/liquidity issues with trading large amts of contracts.
Position traders can easily generate the same returns on say 100k account as a 1mill account due to the fact that inital slippage and commish doesnt really impact a pos trader that much and they can trade many indexes at a time.