More efficient are Radeon 5700XT with under 100Watts consumption for around 51MH, but more cards needed.

I have my second personal rig with 4 x1050 ti plus 2 x1060 3gb. Anyway I want to talk about the 1050 ti and why it can be a good choice together with ASROCK H110+ PRO BTC which supports up to 13 cards.

1050 ti-s are usually 180 USD at ebay but you can find them a bit cheaper on local online marketplaces at almost every country. My personal test with them both cards ASUS EXPEDITION, GIGABYTE G1, ZOTAC keep an awesome level of overclock through MSI at +950 memory, making 14.6mhsh/147mhsh---mining eth/pascal.

6 of these cards can make about 88mhsh/900mhsh together resulting in about 0.00093 btc daily through Nicehash. Electricity is super cheap as these 6 cards only consume about 400 watt and together with other parts they go to 500 watt.

Now double the amount to 12 cards and they consume 800 watt and together with other parts is 900 as one board will keep all of them.

Making 0.00186 btc daily for 900 watt it is a winning bet if you ask me.

So to original OP , your idea is great, the only thing you need to change is the card, from 1050 to 1050 ti as the 1050 ti is a big improvement compared to 1050. You cannot mine ethereum nor dual mine with the 1050.

Forget Zcash and jump in the dual mining arena, there is where these cards shine.

I have a 1050ti mining right now and it struggles to be profitable, I imagine the regular 1050 will be worse.  Seems like 19 1050 would be a lot of hassle for little reward