A schematic illustration of the reconnection layer model used in our simulations. Electrons are sampled from plasma inflowing with v_rec = 0.1c (﹩\pm \hat{z}﹩, green/dashed) and from plasmoids outflowing with transrelativistic velocities (﹩\pm \hat{x}﹩, blue/solid). In our simplified model, these regions are not spatially separated but are sampled with equal probability.