Milwaukee Beers: Reference to BASEketball.

Second Winnipeg Black Bears

Houston Conductors: Reference to Houston’s history as a railroad hub.

Charlotte Royals: Self-explanatory.

The Milwaukee Zeppelins - playing off the German theme, Milwaukee was also an early hub of the zeppelin travel craze.  

The Manitoba Mastodons - an inhabitant of Manitoba during the last Ice Age.

The Houston Bats - in an attempt to stray away from the Space and Oil theme, named for the large colonies of bats in Houston.

The Carolina Reapers - named after one of the hottest peppers in the world.  Technically from South Carolina, this team is named for both of the Carolinas.  Charlotte is the perfect city to rep both.  

 

Milwaukee Chieftains: I know Native American themes can be controversial, but I feel Chieftains can be done tastefully.  Plus, the name "Milwaukee" comes from the Algonquian language, so a Native team name for this city could tie in nicely.  

Manitoba Mastodons:  Seconding this one.

Houston Suns: I know the space theme is a bit overdone with Houston, but I rather like this team name.  Plus, Suns can work both for the space theme, and also for a hot environment theme as well, (this is in Texas after all).   

Charlotte Crowns: Going with the royalty theme here.

Rejoice I shall!

Milwaukee: I don't know much about Milwaukee, but maybe something like Schooners or Bridgers. Apparently, Milwaukee was home to a bridge war in the 1840s and I think both of these names tap into that unique side of Milwaukee history.
Winnipeg: Black Bears is great, but I'd like to suggest just Bears: Winnie-the-Pooh was named after Winnipeg the Bear, so that'd be a nice nod to a beloved character while also staying fierce. Maybe the colors could be gold and red, just like the character.

Houston: I love the name Comets, but that's been done to death, so instead, I'll submit both Talons and Controllers, for the space center. The T-38 Talon is a jet used by NASA and Controllers for Mission Control. 
Charlotte: Both Monarchs and Royals are great, but I'll go in a different direction, something I've been pushing for someone to use for forever: Firebirds. If you don't know, Charlotte is home The Firebird, a statue just outside the Bechtler Museum of Modern Art in Uptown, and it's one of the city's most famous pieces of art. It has an incredibly distinctive look, and is a symbol of Charlotte and its art culture.
[img]https://www.tripsavvy.com/thmb/1hZL0Fq0fieccuPd9t8Hvv1OOeo=/950x0/filters:no_upscale():max_bytes(150000):strip_icc()/744px-Firebird_closeup_Niki_de_Saint_Phalle-59127ae65f9b5864705412e2.jpg[/img]While it looks like a bird with long legs, it's actually a short bird sitting on an arch. (You can see the talons.) I think that this unique form and name could be a great source of a cool Charlotte name that doesn't use the royalty theme or uses Carolina, which I vehemently oppose outside of the Panthers.

Winnipeg Mariners, in reference to the city being on the confluence of the Red and Assiniboine rivers in Manitoba.
Milwaukee Nighthawks. No real reason for this one aside from being kind of a cool name.
Houston Pilots, a nod to the city's aerospace industries.
Charlotte Cardinals, a seconding of a previous suggestion