Even though its only five units, depending on how much their carrying costs are (PITI + HOA + poss MR), I just feel that the buyers of the low-income units will be more vulnerable than the market-rate buyers (ie forced to sell or walk away). These carrying costs added up together are FAR MORE than if the low-income buyer was simply a tenant.
If the five units were going to be occupied by tenants renting from a local housing authority or agency, I would opine that these units won’t affect either the marketability OR resale-ability of the market-rate units. In coastal CA counties, these rent-subsidized tenants seldom cause ANY kinds of problems because they would be in danger of losing their (lifetime) voucher upon eviction. Thus, depending on location, they will likely remain for many years.