Moving off Premier leagues for a second, that's my main gripe with cricket in Yorkshire - lack of depth. Yorkshire is a huge county but still has too many leagues and as a consequence the talent gets spread more thinly than anywhere else I have played. While the 1st XI standard can be very good, you don't have to dig too far into the 2nd XI to see some very poor players. We had a few guys net with us from so called "big clubs" in the main leagues and for 2nd XI cricketers they wouldn't get a look in at that time. I don't think the same joining of leagues has taken place or merging of clubs as in the South East. Therefore you almost have too many teams with too few quality cricketers. That said, I believe the ECB Prem setup in Yorks is pretty robust, even at 2nd XI level. I believe Ryan plays 2nd XI for a Prem club and is very good cricketer.
Lack of depth? I think you meen too much depth. More cricket is played in Yorkshire per square metre than any other county (or at least that used to be the case).
A missing pyramid structure has meant that the differing leagues have vastly differing standards. The teams that consistently reach top few places in York Prem have no where to go. Therefore those players look to move leagues (mainly to get paid). The standard in the Bradford League is probably higher purely because the amount of paying gets done.
A few years ago, pros and overseas were allowed, but this was causing clubs to overspend in an attempt to challenge the league. Anyone who didn't slipped down the league. Now it is back to amateur, the teams have equal chance. One team inparticular wanted to join the Yorkshire League, but was refused in the end.
To go back to the point about too much choice. York has 2 leagues. York Senior League, which has 8 leagues currently and covers teams on the square from Castleford up to Thirsk, across to Scarborough and down to the Humber (and on to Goole). It also has the York Vale league, which has 5-6 leagues and not as spread out. There are a few 1st teams in there, and several 3 & 4th teams. Although there seems to be a number looking to move to the YDSCL.
Therefore, what you end up with is cricket for the masses. Leagues which cover all standards, which is great for the game. The issue you get is some players want to be a big fish in a small pond so will stay at clubs and outperform each year rather than find the right standard., and vice versa, players who will never make it trying to play in teams that are too high in standard.
If you could merge all the leagues into one massive structure, you'll find the teams wll find their level and there would be a more competition of a higher standard everywhere.