With stable jockey Harry Cobden preferring the claims of favourite Bravemansgame, the ride on the smart Hitman was up for grabs.
With Twiston-Davies, a former stable jockey at Ditcheat himself, having stepped into the breach to ride Clan Des Obeaux to win the 2019 King George when Cobden rode Cyrname, connections of Hitman, many of whom are involved with Clan Des Obeaux and include Sir Alex Ferguson, have reached out for a familiar pair of hands.
There will be a third runner from the Somerset yard in the race, a previous winner in Frodon. His usual partner Bryony Frost is currently on the sidelines with a broken collarbone. While she hopes to be fit, Nicholls has nominated Lorcan Williams as her replacement if not.
Nicholls said: "Harry will ride Bravemansgame, Sam Twiston-Davies will ride Hitman and Bryony will ride Frodon assuming she is fit, if not Lorcan Williams will ride Frodon. He is sitting there as a first reserve.
"Lorcan rode Hitman last season, but Sam has won big races for Ged (Mason) and Sir Alex. Harry, at the moment, wouldn't get off Bravemansgame to get on Hitman as he has won those Grade Ones on him and he is very happy to ride him
"He only wouldn't ride him if he didn't run. Hopefully everything goes right next week and we look forward to the big day. If it is good to soft ground or soft ground it will be perfect.
"Bravemansgame probably deserves to be favourite as he has won this year and he has won the Kauto Star around the track and he seems to be progressing, but at the end of the day they don't know what price they are."
Nicholls was already dreaming of sending Bravemansgame to this year's King George immediately after he beat Ahoy Senor in the Kauto Star Novices' Chase 12 months ago.
"He won at Kempton last year and the track suits him well, a flat right-handed track. I've always thought this would be Bravemansgame's target ever since he won the Kauto Star last year. He has always been prepared for it," said the champion trainer.
"It probably is his toughest test as he gone through his novice races and he has won his first race out of novice company this year. He is now into the big boys league in the biggest race there is over Christmas."
While Hitman's class is not in doubt, his stamina perhaps is and Nicholls said: "It is the unknown (going three miles), of course it is. We know Bravemansgame gets the three miles well at Kempton and he hasn't yet, but he got the trip well at Haydock the other day and I think he is crying out for this trip.
"I think up to now he probably hasn't been man enough or strong enough to get the trip, but he is ready now."
As for Frodon, one of the most popular horses in the yard, Nicholls said: "He won the race two years ago, but he is not getting any younger.
"He was never right last season after he ran at Down Royal, but a lot of ours were not right in the spring. He got injured in the Ultima as he got jumped into.
"He had a nice break came back and won the Badger Ales Chase at Wincanton. I ran him too soon in the Betfair Chase but we went up there to pick up some prize-money."