Quantifying the radiative coupling between distant quantum emitters can be relevant for applications in quantum information processing on chip. Here we focus on semiconductor quantum dots embedded in photonic crystal dimers formed by two nominally identical L3 cavities, and we show that the effective radiative coupling between them is relatively robust against non-perfect quantum dot positioning and also, to a smaller extent, to structural disorder in the photonic crystal. We show that the coupling between the quantum dots is enhanced at resonance with the dimer photonic modes and is proportional to the quality factors of these modes as long as the two cavities are strongly coupled. We find that, for the configuration where the L3 defects are aligned along the horizontal axis, the radiative coupling is almost two times larger than the values obtained in previous work.