Pruning advice

Hello!

Could do with some advice on how and when to prune a few things..

Firstly - unidentified type of garden sage - not sure which variety this is - I took a chunk out of it previously and wished I hadn't!  I don't want it to become too enormous but I don't know how and when to prune it.

Secondly - Phlomis purpurea aka purple jerusalem sage - looking a bit spindly but not sure where and when to cut it?

Lastly - cornus alba sibirica - not pruned these really since they were planted two years ago this May, beautiful red leaves in autumn and stunning winter stems. We hired a gardener to help us design a planting plan and not sure what he was thinking here as the remit was to provide screening from the window behind... yet we appear to have shrubs that require pruning to the ground every year?!  What will happen if I leave them to grow up? Will they go brown rather than red?

Pics attached and your advice, as always, much appreciated