Competent Corps Commander
Mixed Division – Competent
2 large Opelchenie Line PC unreformed
1 small Line AC
1 small Light AD
1 small Medium Artillery AD
2 small HC AD
Infantry Division – Competent
2 large Line AD each with artillery attach
1 small Light AD
1 small Medium Artillery AD
Reserve Cavalry Division – Competent
3 small HC AD
2 small Cossacks LC AI
1 small Hussars LC AD
17 units, 38 ACV.
With a low initiative of just 2 (1 for general, 1 for army) I was always figuring on doing a lot of defending, and hence the large HC contingent of 5 small units of Dragoons. In part the thinking was that a significant presence of HC might just deter over-enthusiastic attackers from crossing the centre-line too quickly and thereby buy me some time to set up the game to my preference. By holding back the Reserve Cavalry Division to be deployed last, I could potentially mass the HC where needed to best blunt any appproaches. The 2 jager and 2 cossack units were intended to move forward and slow up the approach also. All fine in theory, but also roundly and completely ignored by all of my opponents in practice

What I did find most useful was ensuring that the 2 large infantry units and the 2 artillery units were all deployed together with the guns deployed into the centre of my army. Also, deploying within the first 9MU of the rear table edge means that your opponent cannot bring your infantry under musketry attack in the first 2 moves unless you move forward. Combined with centrally placed batteries, this allows some scope to come out to meet the approaching attackers. However, I also found that this also means that games will naturally develop more slowly and thus be harder to close out (for both you and your opponent) in a competition timeframe. The most fustrating thing about repeatedly defending was that the attacker has the option to select a river and constrict the table width quite a bit - unhelpful for an army with 8 units of cavalry

Having more than 15 units is useful also in deployment. By deploying the mixed Division first, after 3 deployments the opponent can really only see a big block of unreformed and conscript infantry near your base edge, 2 very forward jager units, 2 central and limbered artillery and 2 dragoon units - and still doesn't know where your effective infantry or the majority of the cavalry will yet go. Likewise, having 2 units to deploy after most armies have finished means that you can save up the cossacks to deploy with a potential end-run into space behind the opposing deployment lines. Indeed, my Cossacks often managed to draw off or blunt resources worth many times more than the cossacks cost.
Even so, the greatest strength of this army mix by far is that it is comparatively large. In 4 out of 6 games, I was a -3 defender thereby being effectively 40 ACV with the opponent needing to break 12 ACV while losing less than 10% of their own army. Given a deeper deployment and the contingent ability to meet the approaching hordes with your better troops means that breaking 12 ACV without taking losses is a big ask ! Quantity is a certainly quality of its own. Conversely, the small HC units aren't that tough (and they really HAVE to be put to some effect !) and I invariably had most, if not all, of them spent or routed during a game so I am thinking that a better mix might have been to have used 2 large and 2 small units of dragoons to add a little more resilience to their role as some of the primary combat units in the army - either that or my competence with using HC is sorely lacking (entirely likely !). Time and again the two large reformed line infantry units were the stars of the show, both in shooting and/or in shaping up or saving a game; they are very tough AND pack a lot of shooting. In conjunction with either jager or artillery to their outside they proved really effective game-influencers.
So, apart from not being an overly patient defender, I am enjoying using the mix and have learnt plenty from sitting on the 'wrong side' of the attacker/defender split. There are some refinements for consideration (inc putting both jager untis into the same division and bringing a charismatic general for rallying purposes - having AD as your elite units leaves a little to be desired).