Yeah, that's why even tho they only have 13 studios available,  they can produce double then that thanks to partnership and outsourcing second party studios. 

nope not 3 to 4 years, I say Max 2 year, just because the first game took 3 to 4 years develop, its not necessary sequel will take the same amount of time. The majority of the development time goes behind researching writing a story, building a world, making assets from scratch and also building a new engine. Almost every sequel has a very fast turn around time and Sony Santa Monica is not a small studio. 

Take A look at Uncharted on Ps3 2007, 2009, 2011 only Uncharted 4 was exception to the rule coz of development issues, but that was offset by a year later with lost legacy. Same goes with Horizon zero Dawn frozen wild and Infamous First light both of them fairly big DLC but was released in the same year. 

So I wont be surprised if we see god of war 5 teaser along with HZD2 at next years PSX ready to launch with PS5

I think its great they show it multiple times, coz it provides valuable feedback on what people like and dislike based on what they showed, if i remember correctly Spiderman had some stiff swinging animation which has been tweaked, early Horizon zero dawn footage was criticized alloy self chattering was kind of annoying, same with Days gone. the biggest one is dreams.. 

Lol @ max 2 years,then hzd2 needs to come out in begin of 2019,never gonne happen,and so wil gow.

Who would have thought?

And several of their studios have 2 teams... so either most of them are already making PS5 game besides the announced games, or we may see sequels to some of the games already launched like HZD2 or UCnew

Exactly this and SONY world wide Studios output this gen are surpassing even Nintendo in terms Quality and Quantity and also they are adapting fast and have more experience more then other triple A studios out there. 

But I still have my concern on VR stuff they should build 3 to 4 more studios that can focus on VR and Mobile smartphones, so their current one will just focusing on PS5. They don't need to buy like Microsoft just created a new based on veteran developer that they already got. 

you do realize HZD had a huge expansion at the end of 2017??? beginning of 2019 makes it just one year!.. again check the dates of any past direct sequels Watchdogs 2014 - 2016, Batman Arkham Series! the division! Forza! Gears! Insomnaic team who made sunset overdrive finished spiderman a new Ip in just 4 years coz they already had an engine. I can keep going! every studio as large as santa monica and guerrilla games are capable of churning out games in couple of years. 

To give you even more context, God of War really began its development in 2014, when their space sci fi game was cancelled and the studio was shifted on to god of war, before that cory had only 10 people who were drawing concept arts.  thats roughly under 4 years! Guerrilla games started horizon Zero dawn in 2011 and went gold in Jan of 2017, so 6 years, and in 6 years they also managed to develop Killzone Shadow Fall and had cancelled another project to work on HZD. 

Make no mistake sony will want these games as PS5 launch titles and 2019,2020 is perfect release window and development time to hit the launch. And I predict that the announcement of these games will be at the reveal event of PS5 and will release whenever the PS5 launches

that's the beauty of showing it early in the development, nothing is final its only after showing it to audience and the feedback it receives, dictates the course of the development. 

If Alloy stuff was always going to be tonned down, then why did they put it in the first place?? 

Insomniac did say they re-did swinging speed after hearing feedback from their e3 gameplay demo last year, and probably the reason there weren't many qte prompts at this years e3 demo.

media molecule on their stream has confessed they have restarted Dreams twice coz even after showing the game many time, people still had no idea what it was and how game creation tools worked. which is not the case now.

For Days gone i don't know what changed, but their game informer coverage sony bend did mention feedback they got after the reveal at e3 shaped the game a lot and what people are expecting from them, and what kind of perception people are having about their game, which was just another Zombie game.

I wish somebody at Sony realizes that instead of buying new studio just hire more developers and make every studio a two team studio, especially their top tier ones, Like, PD, ND, SP, Media molecule, (GG, Japan studio and SSM are probably a two team studio) and also hire back Amy Henig at the newly opened studio who are rumored to be working on the new Uncharted and scout for new talented game directors.