Until he has some good feel and consistency in SIM, why should he go live ? There are simulated environments around these days that calculate your virtual estimated position in queue, so you get simulated fills VERY close to where you would have been filled in live trading. So the fill thing is not a really a factor anymore.
Then you could argue about the emotions of trading live. Well, I think for a scalper in the ES or NQ, who goes for daily profit targets of 50 to 100 US$ per contract, with similar daily loss limits, the emotions when starting with 1 contract live will not go too wild, exactly because of the limited exposure this style of trading comes with. So the emotional and psychological pressure coming from SIM to start trading 1 contract should not be very hard for the average guy.
So it the simulated fills do not differ significantly from the live fills, and the emotions when starting to trade small with this style are also not an issue, why should he then jump into live trading if he feels the consistency is not there yet. Sure he will probably not lose a big amount, but why should he want to lose anything at all if he knows that he is not there yet where he wants to be ?
And a world of hurt when volume picks up again ? There seems to be a great misconception on this forum and the internet in general how very shortterm manual traders (DOM scalpers...) operate. But the way I do it and the way the few others I have seen that trade this way is a very adaptive and flexible one. We are no rigid algos, programmed on a handful of factors, to do A when B shows up. We are a bunch of people that were willing to put alot of work into something, into interacting with the market(s), just because it felt fun to us and we love to do it. By doing so, by all the screen time in front of that boring DOM, treating it like a Super Mario video game, we developed certain skills, just like a player that gets better and better in his game. There are no rigid rules, but alot of experience and a certain feel for the market on the very short term.
This experience also tells you when to go in with 5, 10 or 50 contracts. It also tells you if it makes sense to actually scalp for 1 tick. Or to go for larger targets, in a volatile environment. It is clear that a good trader will not stick to a 1 tick scalping target in a market environment like we had in February this year. In fact, in my thread right when the VIX explosion began, I commented on the much larger moves and intraday swings and that you guys should adapt to this and really make hay while the sun is shining
https://www.elitetrader.com/et/threads/love-this-vix-rocket.317890/
So I really dont understand how you come to the conclusion that a scalper will get hurt once volume and/or volatility picks up. It is quite the opposite... we thrive on this ! Look at the futures prop firms in London: the good traders there have average days in average markets, they make some money, they take what they can, but it is nothing spectacular most of the time. Then suddenly there comes a surprising event, a rate hike, a VIX shock or whatever... volumes goes way up, volatility explodes, and most of these traders have their best days and really pile on the profits.
You guys should really start to understand that a good, experienced, manual scalper is exactly the opposite of a rigid, unflexible algorithm or trading system. He is a flexible trader who is paying attention to the now and here, and who trys to take whatever the market is offering on any given day.