Big problems I see with your setup:
- Jungle left open AND no jungle pressure for your 1vs2 lane which means that lane WILL be dove at level4 without any sort of risk. Additionally the enemy jungler will be able to outlevel solo lanes if he clears fast due to having your jungle as well.
- EXP in mid only 36.6% per player (1/3 exp and 10% lane share exp bonus <-- please correct me if I'm wrong on that assumption. It's 55% exp for duo lanes). Add Zilean bonus and you are at 39.8%
- 2 underfarmed champions instead of only one
TLDR: You will have 3 underfarmed and 4 underleveled champions compared to 1 underfarmed and 1 underleveled champion [Assuming 1vsX lanes are played properly = those are behind and their AD + supp + jungler will be very far ahead of your mid lane]. To make things even worse, you will have no objective control which will put you even further behind.
You lose far too much by doing this. Putting the AD + Support lane mid achieves the same thing (pressure on mid, zone potential and perhaps an early tower) and the support can help the jungler on invades.
PS: Why do you think that shyv is a good 1vs2 laner? She really isn't. No reliable way to farm and no sustain. Her only strength is wave clear but she will be poked whenever she tries to clear.