Sure, you can get to an armistice with Harold and Tammy: Housing costs are high but your salary is such that even spending 66% of your pay on housing leaves you with an ample amount of money.
But I wouldn't call that agreement anything other than begrudging.
This seems like the essential problem. Harold isn't actually a buyer in the housing market; he locked in a fixed-rate mortgage 20 years ago. If he's planning on retiring somewhere outside the city, or to a managed community, he might never be on the buyer's side of the market again.
But he's definitely a seller - that house will presumably be sold or passed on to his kids. Property taxes are a pain, but they're a manageable one for a house bought as an investment. Harold is actively opposed to Roy and Tammy; if their rent doubled that would be a good outcome for him.
We keep treating this like all the residents of the city are a group, but that's not true. Renters own zero units of housing, homeowners own one unit, landlords own multiple. It's not at all guaranteed that homeowners align with renters more than with landlords.