Rolling equity

Have a potential deal where the Seller is happy to hold onto a 25% stake (he currently owns the hole thing through a Holdco) and has suggested that I just buy 75% of the trading entity rather than him rolling his equity into a newco.

Obviously this is quite lucrative for me so I am not particularly motivated to enlighten him but surely he will be advised against this later in the process so might as well inform him now?

Are deals done where the Seller retains the original equity rather than rolling into a Holdco?

Thanks