Odd bug with purchasing the Meadows. It also buys the max number of shepards when you first buy it. Actually may be a more common bug than that. When you buy druids it happens as well, and when you buy any of the '2nd option alternate' buildings you buy 1 employee as well. My guess is it's tied to the hire/max button logic as they would be the 2nd and 3rd buttons on each row.
https://ancillary-proxy.atarimworker.io?url=https%3A%2F%2Fdocs.google.com%2Fspreadsheets%2Fd%2F10bz7chsFfLd-haKTt7GsxxDguXEWcsI7Y6o2AhBOiCI%2Fedit%3Fusp%3Dsharing Spreadsheet to help you allocate your gold.