Hi Dave,
I am certainly not an expert, but if you're paying £10 a trade (for example) for each of 5 funds, you're spending 1% of your investment each year in commission. Have you thought about sticking with the allocation that you're happy with, but investing the whole £5k in one fund, then next year, the whole £5k in the next? That way, you achieve (more or less) your desired allocation over a period of five years and save maybe £200 in the process.