You can also add ribbon code to the styles manager that will add the button to the tab created by the ribbon manager template. You will need to modify the ribbon xml to make this work.
For your ribbon manager:
Code:
<?xml version="1.0" encoding="UTF-8"?>
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui"
xmlns:nsHost="rbnManager">
<ribbon startFromScratch="false">
<tabs>
<tab idQ="nsHost:Company" label="Company">
<group idQ="nsHost:newGroup" label="New">
<menu id="mnuMemo"
size="large"
label="Memo"
imageMso="NewPageOneNote">
<button id="btnCreateMemo"
label="New memo"
onAction="mMemo.CreateNewMemo"/>
<button id="btnEditMemo"
label="Edit memo"
onAction="mMemo.EditMemo"/>
</menu>
</group>
</tab>
</tabs>
</ribbon>
</customUI>
For your style manager:
Code:
<?xml version="1.0" encoding="UTF-8"?>
<customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui"
xmlns:nsClient="rbnManager">
<tabs>
<tab idQ="nsClient:Company">
<group idQ="nsClient:newGroup">
<button id="btnStyleManager"
label="Paragraph Styles"
onAction="ShowfrmParagraphStylesIfNecessary"/>
</group>
</tab>
</tabs>
</ribbon>
</customUI>
NOTE: I have used this method to add items to a custom ribbon that are specific to a particular document template, but I would hesitate to use this for two templates that are in the startup folder as it is not possible to control the order in which they are loaded.