If you want the same style to work with multiple types, you actually need to create a style that targets a base type of those controls. You don't have to constrain yourself to the most derived type. For instance, you could define a style for all Panel types (Canvas, etc), like this:
<Style x:Key="PanelStyle" TargetType="{x:Type Panel}">
<Setter Property="Width" Value="125" />
<Setter Property="Height" Value="55" />
</Style>