4-6 is reasonable but for I feel 5-8 is a bit more sustainable to add some redundancy- though that should include a technical lead who also serves as the manage

4-6 is reasonable but for I feel 5-8 is a bit more sustainable to add some redundancy- though that should include a technical lead who also serves as the manager (50-50) and ideally a product/program person who can maybe float between teams. It's also important that everyone is using the same standardized toolkit and shared infrastructure so each team doesn't invent their own ways of working or tooling. Some flexibility and experimentation is good but it should be clearly segmented until it's clear the innovations are worth the adoption and maintenance costs of both the 'new' and now 'legacy' system.