More scholarly outlets?

Zak started a conversation and Bridget Crawford asks a follow-up: When did it become the case that one post-law school is not sufficient to make one a viable candidate and that 2-3 post-school pieces are the norm? One possibility (raised by Bridget and Glenn Cohen in the comments to Zak's post) is the rise of the VAP and the time and writing expectations it provides.

I want to connect it several changes in scholarly publishing (which may be complementary to the VAP explanation):

   1) There are more outlets for scholarship. Most schools have several journals and the number seems to be rising. The number of speciality journals has increased, including "law-and-policy" journals that publish the same type of public-law stuff that already plays well in general law reviews.

   2) The "typical" article is shorter than it was 10-15 years ago, prompted by the guidelines adopted by several of the t14 reviews. The typical piece is 15-20k words, as opposed to 25-30k. This means, I suppose, that you can write two articles in roughly the time you used to be able to write one.

   3) The rise of on-line supplements and similar outlets for shorter scholarship provides an incentive and opportunity to publish one big piece and one small piece in a year.

I am not looking at FAR forms this year, so I do not know if any of these explanations is empirically supported. But I do know that all 3 have affected how and what I write. So it makes sense that they also might affect what VAPs and others planning for the market do (especially if they are getting advice from people in roughly the same position as me).