I fairness, I'm mining with 100Mhs+ (7 x 1060/3gb and 1 x 1070ti/6gb) and I'm not getting 1.47 coins per day, more like half that. I wouldn't rely on those figures, just buy a bit of mining equipment and see how you go before investing more heavily. Reality is not the same as theory.
agree most of mining profitability calculators lean towards best case to ridiculously optimistic
One of the most effective strategies you can use as a miner is tracking your stats personally, and learning to not rely on WTM. It's just a tool in your arsenal.
WTM uses the last 24hr difficulty for calculations by default, and this is not necessarily going to be accurate for the future due to diff changes, and pool luck etc.
Use a spreadsheet and record WTM projected earnings each day, as well as your actual pool payouts, so that you can start to do comparisons of your actual payout's v's WTM each day/week/month/etc and you will see real world results.
You will most likely start to see that some days you beat WTM estimates, and other days you under-perform, but then at least you will know EXACTLY what's happening for you!