A "grinder" who is on the margin means you are the least profitable trader by definition. Any small incremental cost (loss) removes the marginal player, again by economic definition. I'm simply stating facts here. Maybe you misstated your current positioning, I don't know. But in the economics world, marginal players in ANY business be it trading or selling apples, are the first to go. It's not a statement about your ability or your strategy. It's merely a statement about math.
I think there is a big difference between a guy who grinds out base hits and someone who margins the hell out of their account to make a few ticks/grinds out profits. Two completely different animals. One can base hit trades in a well funded account and not have to margin the hell out of his money. If you are well funded and have the right strategy/discipline/money mgmt you can make a ton of money being a base hit type trader.