I am guessing you are talking about Bar 67 tranquilment RH, bien en dehors LH section?
There are many chords that ask for a stretch of notes not physically possible for most to play. There is nothing wrong with arpeggiating it but with a quick rapid whip, you cannot afford to make it sound sloppy and you should overexagerate the weight of your LH thumb to draw out the accent and support the middle voice. This would take some fine tuning until you produce desirable sound.
Use the Lh 1 and 2 to pick out the middle voice and 4 and 5 to pick out the deeper bass notes and know when the 3rd can be applied for either cases. That is generally the touch you have to master there. When asked for big chords you generally want to give the upper part of the chord more importance so that you don't distort the middle voice.
There is no point talking about how the hand should move because its simply too difficult to express in words, but everything you do has to be comfortable and controlled. You have to have a good sense for your centre of your hand and from which point you pivot your hand at, an invisible balance which controls the deeper bass of the LH and the middle voice of the piece (upper part of the Lh).
Don't be overly stressed if you cannot hit all the notes at once, learn how to play it musically but still play all the notes. If you do a good job of it no one can criticise you. It would look funny if you started using your feet to play a note or two just so you can get all the notes at once so find a way to adapt it. The multiple voices which ask for difficult hand positions is what Triana a tricky piece, so don't be suprised when you hit slow learning curves periods.