Your crazy imo haha
1070's ? dude your like a YEAR too late to build a farm with those lol, you are gonna be lucky to ROI probably before they start bring in like 1$ a day each

Plus all that wasted space, did you not consider DENSITY LONG TERM?
New mining specific cards are coming out that are gonna DUST your whole farm if you have 1070's, did you consider THAT?
Im just getting RID of my old 1070 for POWERFUL cards, 1080, 1080ti, and stacking my coins for the new mining specific card + volta and vega
Like you literally picked the worse time to choose 1070, o and in 2 months or less they will be 1/2 price