You can use prep TLC for close compounds.

Try using serial fractionation approach. Fractionate your cluster of compounds to separate if from clutter (fractionation 1), then further fractionate the fraction (with your compounds of interest).

I agree with dr. Jamwal but you should try the fractions by dimensional TLC to check how the separation is going run

I do agree with you dr. Ola. Fractional  study need to be done using dimensional way.