No need to pour on the water and chemicals. However, rotary mowing will make the turf look bad as well as open it up to weeds. Less chemical inputs are needed on reel mowed turf in my experience. A rotary at 1" will work if your ground is countertop flat. No promises on how much it will tear up and thin out the lawn. I like rotary mowers for renovation jobs. There, I use it to tear out and vacuum up the excessive material in the lawn. A normally graded lot will do a lot better with a reel, preferably one with front and rear rollers. My preference for a greens/sports turf grade reel mower comes from how it will track over variations in the ground with less scalping vs a homeowner or landscape grade reel. Most of the lawns I mow with my reel are ones that have been condemned as too uneven to mow with a reel. That is because a Tru-Cut will not work on anything other than countertop flat lawns.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738