Is ranking not tied to views? When you upload very often, I feel you're sharing a bunch of views between a lot of videos. With a small channel, the result is a bunch of videos with 20-50 views.
if it was tied to views. then how would a new video ever get found lol
i just wrote a big guide on SEO - found here this is all you need
http://yttalk.com/threads/how-to-seo-titles-descriptions-and-tags-full-guide-with-example.223822/
lets take an example. a channel with 100 subs. firstly its wrong to assume that if you upload 1 video and your 100 subs all watch it but if you upload 3 videos each video would get viewed 33 times each. subs will watch what they are interested in. yes i agree overkill is generally not a good thing. 1 a day or less is perfectly fine. once you start regularly uploading 2-3 videos a day you might start to struggle to keep subs because subs don't like getting spammed. nothing to do with rankings
a good title, description and tags are what makes a video get ranked. then analytics starts looking at your viewer retention, for example. i do a youtube search for "big boobies" i get a load of results. i click the top video, if after 10 seconds i realise their is no big boobies in the video i might click off. and if that happens a lot, that video will fall in the rankings. youtube introduced this to stop clickbait title and thumbnails
engagement is also important, likes/dislikes and comments help you rank better because youtube likes engaged viewers. thats why call to actions are important, like and subscribe etc
if lets say two channels upload the same video, same title. same tags, same description. then the channel with more subscribers will usually rank higher. and viewers also have a marginal effect. but that is for a video thats identical in every other way. in reality that does not happen.
so yes. having a smaller channel with a smaller sub base puts you at a disadvantage, but that can be easily overturned with better SEO. the multiple uploading of videos a day thing does not really come into play
hope that explains it better