There were about 6 years of development creating the features that need overhauling.
Programming the groundwork in which all of these features are built on took most of that time, actually.
The line between the current features and the overhauled features is a tiny one compared to the line between the current features and Tanaka's early concept papers.
Some signs point to the game having been in full development for only 3 years, as well. There is that 2005 concept video that showed off their new game engine, yet that engine (that this game uses) has caused them a lot of trouble, and not just for this game.
Their team may have also been significantly smaller for a majority of that time. Before the game engine is ready it's quite hard to try to make a game with a full taskforce.
There are simply million reasons for why you can't compare the development time so far to development time in the future 1:1.
I don't know why you keep mentioning what they did in the past though. Only the present and future matters at this point. Past is past.
It took about a month to overhaul the original battle system and that was during part of the buggiest phase of testing.
The Alpha system was not changed after March, the Beta begun after E3 in July. How this translates to "a month", I don't know. That's simply what you would expect from an overhaul, especially if it relates to everything in-game and is not just about one feature that is separate from the rest of the game.
It doesn't matter how long the issues have been known, they have been only in development since January or probably even February. That's when Yoshida took over and got his development structural changes done, as well as restarted the process. Only Company system was kept over from the old schedule.
The fact is that this game needs lots of changes and the old team were already working on fixing them. Yoshida took over and decided to change the priorities and fix other things that need fixing first. There are still issues we and they are aware of but they can't fix everything at once. They might have the money, but they don't have the manpower and it's not easy to bring lots of new people to a project just like that, especially when the company has other projects to deal with at the same time.
3 months- a maximum of 4 months- is what they need to get this stuff in such shape that it can be presented to us. If we don't see the real fruits of their labor in May, they are being too slow and the game is as good as done, regardless of what they can do in the future. Until then, though, it is completely reasonable to not expect to see said overhauls but smaller improvements that take less time to finish instead for the time being.
I'm still expecting Companies in either 1.17 or 1.17a though, they have been in the making for longer than the rest. Edited, Apr 12th 2011 5:22pm by Hyanmen