You'd still remove a lot of flexibility.
In theory, in a "bring 6 pick 4" format, you can pick between 15 combinations of 4 Pokémon.
Playing a combo such as Lillikoal already reduces that flexibility, you'll virtually never bring Lilligant without Torkoal. So down to 11 combinations.
Now you're considering adding Urshifu-Water, that you'll never bring alongside Torkoal. 5 combinations left.
Reducing from 15 to 11 in order to bring a good combo is a compromise. But reducing from 11 to 5 because "I made one today" is a waste. Also in those five options, only one plays Urshifu. Whenever you want to bring Urshifu, your other three teammates would be "forced" to be not LilliKoal.