Yes, it's incoherent and inconsistent. For example, Lancaster went into Lockdown 2 with just over 200 new infections per week per 100,000 population, but on a downward trend, and lobbied to be in Tier 2 when they came out with just over 100 per 100,000. But they had to go into Tier 3, the same as the rest of Lancashire because it would be too confusing and difficult to enforce.
Luton, meanwhile, went into Lockdown 2 with just over 250 new infections per week per 100,000 population, but on an upward trend, emerging on 280, nearly three times as many infections per 100,000 as Lancaster, and went into Tier 2. Luton is a unitary authority, so it would have been simple to have Tier 2 for the rest of Bedfordshire and Tier 3 for Luton. (See this newspaper article: Luton has higher infection rate than nearly 80% of Tier 3 areas. The latest government announcement has all of Beds now in Tier 3.)