Sorry xela I have to agree with bpr here. New traders are likely going to blow out their first account regardless of the size of the account. Might as well take a loss that can be recovered from.
$25k and to know what they're doing. CL isn't ES. Here you exaggerate a little, of course (as you know perfectly well), but I agree with the underlying principle behind the point you make.
Just...Don't...do it. There is no "recommended" account size. There is only what you could stomach when live, watching your trade fall into the red or rise into the green. The only way to know how you will fare is to try it with real money, but in something simple. Like MGC. I would not be surprised that if you put 10K into your live account, enter a single contract position in MGC, and see it fall 50 tics ($50), that you would sweat. Because if it was a full-size GC, or regular CL, it would be $500. But watch yourself when you lose 50 tics in MGC in an open position, and check yourself while it happens. No need to bleed profusely discovering what you can or cannot do when real money is on the line. TAKE IT SLOW.
I hear you. My personal preference is 20K per Contract /yours 25k per Contract. Close enough ... But again this figure is for successful traders who have established their edges . For established trader the goal is to smooth out equity curve , reduce risk and protect capital...etc..etc.. It may sound very odd but for a newcomer this figure is not appropriate ... For a newcomer the goal is not to make money but to prove their edge it may take them dozen attempts before they finally do it if they are lucky .... They might have to top up their account many times ... so a lesser figure is more appropriate, as they prove their edge and grow their account they should reduce risk gradually and trade 20k/25k per contract...