Water-based paints are self-leveling and don't like to be over-worked. I'd sand and repaint. Give it a full coat, not spreading it excessively or letting it build thickly, finishing the back-stroke with only the tips of the bristles. It will self-level and most of the brush strokes will disappear all by themselves.
I've brushed oil-based alkyd enamels to a near mirror finish with almost no brush marks visible unless you looked really hard. You see just a little waviness which spraying doesn't give. Penetrol, just enough thinner to add working time, work fast, and lay off back into the wet at about a 30 degree angle of brush-to-surface keeping the brush flat, but pulling away gently. It's the laying-off (some call it "tipping") that makes all the difference and I've not yet found a water-based paint which would equal this.
One mistake means re-doing the entire area, Going too slowly and letting the paint 'tack' means the same. And a couple days wait before you can re-do it as oil paints fully cure more slowly than latex does. Your cost is 2.5X a brushed latex job plus materials. My cost is stress: it's the most demanding work I've ever done requiring your full concentration and no slowing of speed. After half a day of this it's time to go home; you're shot mentally and physically. Many skills of painting have been lost since latex paints took over. Brushing oil-based paints is an entirely different game and most painters don't want to touch the stuff but it is perhaps the most durable good looking gloss job there is, and it's de~rigeur for restoration work because that was how it was originally done.
Phil