"Single tier" works just fine. No pumps here.
I do use gravity to collect the runnings into the grant and to transfer the wort into the fermenters, so it could technically be viewed as "two-tier" for some aspects of the brewing process.
You just need to use plastic scoops or pitchers to transfer hot water into the mash tun and to perform vorlauf.
2 quarts at a time, but I don't mind. By the time I would have my pump and hoses in place, I'm already done manually.
And it is one less thing to clean.
I use a 5.5 gallon (22 quart) SS pot as my "grant" to transfer the runnings into the 20 gallon SS kettle sitting on top of the banjo burner which sits on the same sturdy patio table as the two round 10-gallon Rubbermaid coolers.
The patio table is made of steel and tile and weighs >200 pounds. It won't melt or break and it is easy to clean off afterwards.
There's minimal bending over or standing precariously on stools or ladders. And less clutter--the 5.5 gal SS pot and the two fermenters and the 5 gallon bucket of Starsan remain out of the way until needed under the table.
There's no need to heft anything more than 4 or 5 gallons at a time during brew day.
Be it pouring the RO water from the plastic carboys into the boil kettle or transferring the first (or second) runnings into the boil kettle (via the 5.5 gallon SS pot) or straining the wort into the fermenter via the BK spigot.
There's no need for me to build a Brutus, IMO. But they sure are sexy, I'll admit.