to lessen the load on the rotor you can install an antennas direct 91-xg as an alternative in place of the cm4228. That is what I did at my home a few weeks ago.
I am using my old winegard hd8200p for vhf and the 91xg for uhf with amplification. I am very happy with the uhf performance of the 91xg.
The vhf performance of the cm3671 is ok but the vip306 may perform better.
if you are concerned about the rotor (the cm9521A is not my cup of tea) you can order an alliance u-110 rotor and "clunk - clunk" control box and thrust bearing from here. They have alittle more muscle and will last forever. I have used one for about 20 years.
http://www.rotorservice.com/prod1%20rotor%20sales.htm
enclosed is a picture of my current install to illustrate.
You are not really considered fringe (after looking at the antennaweb results). if these figures are close to your reception parameters, the cm 3671 should be plenty and the cm7777 preamp a risk at overload because of the stations in yellow. A winegard hdp269 would be better actually.
* yellow - uhf WMYV-DT 48.1 MNT GREENSBORO NC 201° 10.7 33
* yellow - uhf WFMY-DT 2.1 CBS GREENSBORO NC 206° 10.9 51
* yellow - uhf WXLV-DT 45.1 ABC WINSTON-SALEM NC 201° 10.7 29
* yellow - uhf WXII-DT 12.1 NBC WINSTON-SALEM NC 314° 41.3 31
* yellow - uhf WGPX-DT 16.1 i BURLINGTON NC 31° 17.2 14
* red - uhf WUNL-DT 26.1 PBS WINSTON-SALEM NC 314° 41.3 32
* red - uhf WCWG-DT 20.1 CW LEXINGTON NC 201° 10.8 19
* red - uhf WLXI-DT 61.1 TBN GREENSBORO NC 201° 10.8 43
* red - uhf WGHP-DT 8.1 FOX HIGH POINT NC 202° 14.7 35
* red - uhf WUNC-DT 4.1 PBS CHAPEL HILL NC 115° 35.7 59
fringe would be more like all blue and violet.