Agreed I definitely learned more about Vita. ZhugeEx's analysis relies on an assumption, so it's no better than your's or mine. I mean you are implying a dying console which just sold 4.1 million the year prior some how sold more or even stagnated being a year older and missing an entire quarter due to it being disconitued that very year? ZhugeEx made that assumption due to Sony not mentioning the PS2 in a blurb where Sony says the "primary" reason for the decline is due to our current consoles. Sony literally mentioned PS3, PSP, and Vita. I'm not sure why you would expect Sony to mention their recently completely discontinued console, which was also missing a quarter of sales as a "primary" reason for declining sales. Not being mentioned as a primary reason doesn't mean it also wasn't in decline. It's decline can't be significant or even contribute much to the overall decline because its a dead console and was literally discontinued that very fiscal year.This video is for PS4 PS3 and Vita only, it might be useful for those who want to know more about the Vita.
But ZhugeEx's analysis of the PS2 is far more relevant than other theories, what he says makes sense.
We know that the PS2 was 155.1 on March 31, 2012.
For the following year Sony announced 16.5 million (combining PS3+PS2), the year before it was 13.9 for PS3 and 4.1 for PS2.
Sony mentioned in its reports a significant drop for the PS3 in that year, and didn't comment on the PS2.
Let's say the PS2 stagnated at worst, so that's 4.1 as in 2012. That leaves 12.4 for the PS3 in the best-case scenario.
155.1+4.1 = 159.2 at least
Edit: Also Sony didn't say the PS3's unit sales decreased significantly, they were describing a significant decrease in revenue. Sony only mentioned the unit sales for PS3 were down but never said significantly. So really all the PS3 has to be is lower than that 13.9 from the year prior. If it was 13.8 for example, that leaves 2.7 million for PS2. This is why we can't just take ZhugeEX's ananlysis and just believe it because people can interpret data very differently. I'll repeat that blurb with significant was not describing the PS3's unit sales, so the PS3 was down but to what degeree we don't know. So really the range should start at 157.8 million atleast for PS2 but have no cap due to us not knowing the degree of the PS3's unit sales decline.