From what I can see the only real difference would be the psychological impact of people looking at Neymar and thinking 2 shares at £7.50 is more reasonable than one share at £15. Other than that point, if the dividends drop then it makes no difference if it happens or not.
The only question I would have is that if the current price rise algorithm would stay or change to reflect the new values. We currently believe that if you buy 100 the price will go up 1p, although we have been told it is slightly more complex than this. Would we now need to buy 200 to get the same increase?
For example Salah is £10. If I buy 100 it goes up 1p. I have spent £1000
Share split happens, Salah is £5, I buy 100 and the price goes up 1p. I have spent £500.
If this is the case then this would effectively double the speed that prices rise back up as every £1 invested after would have been worth £2 before (only in this increasing prices example).