import ops

class HardwareObserverCharm(ops.CharmBase):

    def __init__(self, args) -> None
      self.hardware_exporter = HardwareExporterService(self)
      self.smart_exporter = SmartExporterService(self)
      ...
      

class HardwareExporterService(ops.Object):
    
    strategies = [StrategyClassA(), StrategyClassB()]
    
    def __init__(self, charm):
        self._charm = charm
        self.framework.observer(self._charm.on.install, self._on_install)
        self.framework.observer(self._charm.on.config_changed, self._on_config_changed)
        
    def _on_install(self, event):
        """Install resources and exporter service."""
        for strategy in self.strategies:
            strategy.install()
        
        # Install exporter service
        ...
        
    def _on_config(self, event):
        """Configure."""
        # Render/Set configurations
        ...


class SmartExporterService(ops.Object):
    
    strategies = [StrategyClassC(), StrategyClassD()]
    
    ...