Old Glory horses vs Perry horses comparison

Mark, a wargaming buddy of mine, wants to do some American dismounted dragoons for the War of 1812 Battle of Sackett's Harbor.  No one does these and so he will attempt to create some from the Perry Napoleonic French version.  With this he asked "How do the mounted OG & Perry Dragoons compare size-wise?  Any idea? Are they acceptable if kept in the same unit?" 

I will let the attached photo demonstrate that the Perrys are much larger; especially their cavalry.  And correctly so IMHO.  Most metal versions of horses, and this is particularly true of OG, are horrible examples of the species.  However as a grouping I guess they do the trick but cannot be mixed with many other manufacturers.

Old Glory American Dragoons from their War of 1812 range (left) although the horses are used for many of their ranges I am afraid.  Perry plastic (right) from their French 'heavy cavalry' box.

As the OG horses are quite short in stature, the dismounted Perry dragoons are  quite tall in comparison.  But they would be separate units.

The photo - rather poor rushed as it was to provide him with a quick answer- is from table view and the figures are at an even level.  The figure on the right is a French General I built from a cuirassier but the horse would be the same as their French dragoon version and the dragoon riders would be the same size.