How to get text-alignment and stretch in the dockpanel correct?

In a xaml DataTemplate I have

<DockPanel >
    <StackPanel DockPanel.Dock="Right" Orientation="Vertical">
        <Button />
        <Button />
    </StackPanel>
    <Grid VerticalAlignment="Stretch/Center">
        <TextBlock HorizontalAlignment="Stretch"
                   TextAlignment="Right"
                   Text="{Binding ...}"
                   VerticalAlignment="Stretch"
                   DockPanel.Dock="Right"/>
    </Grid>
</DockPanel>

The dockpanel is horizontal, i.e. stackpanel is to the right, the grid to the left.

I need the two buttons to stretch each to 50% of the vertical space of height of the dockpanel. How do I do it?

A schematic picture of want I try to achieve. The controls are meant to stretch to the borders as much as possible.

I need the textblock to stretch to 100% of the vertical space of height of the dockpanel and it's text to be vertically centered. It doesn't work bc. in the case of Strech I get the 100% space but the text is vertically topped and in the case of Center the textblock is not stretched.

A TextBlock cannot both "stretch to 100% of the vertical space" and also be vertically centered. It's just text after all.

You should be able to get rid of the StackPanel and replace the DockPanel with a 2x2 Grid. Something like this:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="2*" />
        <ColumnDefinition Width="1*" />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Button Grid.Column="1" Content="Button1" />
    <Button Grid.Column="1" Content="Button2" Grid.Row="1" />
    <Grid Grid.RowSpan="2">
        <TextBlock Grid.RowSpan="2"
                   TextAlignment="Right"
                   Text="Text..."
                   VerticalAlignment="Center"
                   HorizontalAlignment="Center"/>
    </Grid>
</Grid>