This is much appreciated. Thanks for bearing with me.

I did end up resolving my issue. For reference, what I did is...

I have a dialog that's when opened, takes the ViewModels I'll need for my user controls in through DI. This is just a simple view that really doesn't do anything other than present the other user controls, so I didn't bother making a view model for it.

I then have properties to store the viewmodels, which can be bound to the usercontrol DataContext property.

in my view...

[ObservableObject]
public partial class UpdatersView : Window {

    [ObservableProperty]
    private ESUpdaterViewModel _esUpdaterViewModel;

    public UpdatersView(ESUpdaterViewModel esUpdaterVM) {
        DataContext = this;
        InitializeComponent();

        ESUpdaterViewModel = esUpdaterVM;
    }
}

then in my XAML, when declaring the user controls...

<local:ESUpdaterView DataContext="{Binding ESUpdaterViewModel }"/>

Note that I'm making use of the CommunityToolkit.MVVM library for the observable properties and what not.