Austrian regimental collars is something you need to think about.
One regiment has drie bataillons, the 1st and the second = 6 bases, the thirty battalion (depot) has 4 bases. Each regiment has for bases of grenadiers. So 2x6 bases + 1x4 + 1x4 grenadiers. With the 1-3 battalions, together 16 bases, you can form 6+6+4 or 8+8 or if you add 2 bases militia, you have 3x6 battalions, whatever you what to play with Lasalle Black powder or other future games. This is a flexible way of using your Austrians.
That is how i painting my austrians.
Besides that you have you grenzers battalions, and also your militia or Landwehr. Grenadiers are concentrated in one place from several regiments, the equivalent of the french old guard.
Also creating a 28mm Austrian army. Greatings from Belgium.