you know very well what she meant. That Sugizo might not have been fully versed in all X songs at the beginning. The dude has a gazillion jobs besides X Japan. I'm pretty sure he wasn't even 50% ready to tour with them when they started the whole "let's go overseas" stuff.
Exactly, as far as I remember it, he actually played the wrong progression of powerchords(like simple chords) in the verse of "X", which seems kinda embarassing. Toshi wasn't in good vocal shape, either(now he totally is). They would have needed more time to rehearse, but once contracts are signed, you have to deliver. Got way better on the World tour!
When the band isn't working together for a long time, they don't "fit" together. I have the 1994 DVDs and those concerts were extremely produced and awfully performed. Heath bass out of tune, Toshi's hoarse voice, Yoshiki missing simple stuff like the piano start from Endless Rain. When they got back rehearsing together for a longer period on Dahlia Tour, their performances were awesome again.
The first concerts after the reunion were quite messy. Let's remember that on the reunion concerts in 2008, Yoshiki said that would be 10 guitarists playing the different songs. On the last minute he said that the production had lots of issues, there is no enough time to rehearse and everything with all of them, then he announces Sugizo and the WTFiest guests ever, Wes Borland and Richard Fortus, which basically "appear" and play power chords, while almost the whole concert had hide playback. Sugizo confirmed this story in an interview later, saying that even Miyavi (ugh!) was intended to be there but there were some issues caused by the lack of time.
The 2009 concerts were awful. Everyone doing lots of mistakes, Toshi's voice was really bad (strong pressure from HoH to release 896419 albums each month), Yoshiki himself made mistakes on almost every songs (oh, that disastrous performance of Dahlia...)
Things started to get better since 2011 as they are spending more time together in the tours, rehearsing together. During the 2009 crisis with Heath, him and Yoshiki said in different interviews that 'kept rehearsing for the upcoming concerts', but each one alone with recordings. Is never the same thing as everyone working together.
Since 2015, despite the age and Yoshiki's health issues, they are in the best shape since the reunion. Lunatic Fest and Wembley concerts were the highlights (and even on Wembley Yoshiki missed the final part of X making everyone confused... but was somehow hilarious). Even the acoustic tour, which they had so little time to create new arrangements for most songs, were amazing. Sugizo even sang the backing vocal part of Heath (never understood why he doesn't even have a mic since the 2011 tours), showing that he can sing these backing vocal parts without the need of those awfully recorded parts of Last Live.
When a band work together as a band, everything goes smoothly.