Say you scalp with a 4-pip stop. Your round-trip cost (spread plus commission plus average slippage) is 1.2 pips. That means cost alone is 0.3R on every trade, before the market does anything.
Now you aim for a 0.5R target, which is 2 pips.
- Winning trade: +2 pips minus 1.2 cost = +0.8 pips net, so 0.2R.
- Losing trade: −4 pips minus 1.2 cost = −5.2 pips, so −1.3R.
Change the target to 1.5R (6 pips) with the same cost:
- Win: +4.8 pips, 1.2R.
- Loss: −5.2 pips, −1.3R.
So small targets aren't wrong in themselves. They're wrong when costs are a big fraction of the stop. Either widen the stop and target together, trade at times when costs are lowest, or switch to a cheaper instrument.
What's your cost as a share of your typical stop? If it's above 20%, I'd be very careful with small targets.