The moral boost this tournament gives is probably neutered by the fact that when Real return to Spain, they probably will find themselves 3 points further away from Barcelona, yeah with a game in hand, but that just means they won the game you have in hand so you need to win it when time comes due, adds more pressure in the league race.
And not only that, this is a break in the team training and they will play that in hand game in a tougher part of the season schedule-wise, if they won this world cup with authority, Ronaldo scoring 5 goals in 2 games and Real blazing through both matches I'd say they could come back stronger mentally in January, but as it was I think the little morale boost does nothing compared to the problems this title might bring them in the future.
When it comes to a knuckleball, every shot you hit where the ball takes effect and has power is "perfectly" hit, the problem with that technique is that you're basically unable to aim it.
The shot depends on unpredictable ball effect so aiming it is not an option, you have to hit it well and pray it goes between the 3 posts, difference with a more technical hit like that one or the old-school one like Mihajlovic is that you are putting less power on the ball to improve accuracy, but keepers can predict the only spot you're sending 90% of your shots, unless you become Ronaldinho, who basically could change the angle of the goal he was aiming for without giving the GK a clue in his shooting form.
Still, if the knuckleball locks into a good direction, keepers have their chances to block it drastically reduced compared to a standard shot as it makes the ball a threat in the whole goal area, not just the corners. If you're looking for raw numbers and scoring, not just fine tuning, knuckleball may be a good option as the rest. Even professional catchers in the MLB have problems to catch knuckleballs from their pitchers, and those guys are basically trained their whole pro life for that specific purpose.
Also, it's probably next to impossible to alternate between a knuckleball/finesse style in the same game as they take different routines, first because changing between both might throw him out of the ideal shooting form, second because that means he'd have to train 2 types of FK instead of being specialized in one, and lastly because even if he managed to nail both routines to look similar in the approach to the ball (which might me detrimental to both shooting forms) any keeper with enough video footage could probably predict if he was shooting to "break" the ball or to aim it just by observing how he runs into the ball.
So, I guess when it comes to his decision he basically could've thought that if he wanted to go for volume and not quality like barely missing above the post, the knuckleball makes better use of his body (strong and long legs who act like a whip to shoot with more power) instead of pinpointing the ball, which could be easier to do with shorter legs (leaving Ronaldo with a natural disadvantage against shooters like Leo, Pirlo, etc).
