The trick in selecting the best cavalry unit for your demand is to check their abilities before recruiting. There are in fact two types of heavy cavalry. The ones with spear and the ones with sword. The sword ones tend to expand more and more as your technology advances, but there will be only one or two types of heavy cavalry with spears. Now, if you intend to use the cavalry in the positions where you need quick resolution of matters, like disabling cannons or flanking the enemy from back, you may want to use the ones with sword since they are better in close combat, after charge.
However if you want to use the charge efficiency on flat ground before your musketeers get into position, to either give them time or to gain the upper hand. You may also want to flank just through the enemy formations with wedge formation cavalry unit, get behind them to make sure a flank in case they continue to walk the way they were already walking. At this time, if they turn back to fire after your cavalry unit, this might as well mean their doom, because a cavalry unit which flanks through line infantry does not lose much of its speed, therefore as the line infantry messes with itself for turning back and reforming for a salvo, the cavalry unit can easily get the hell out of their range which is the exact time that your own line infantry can close up and fire from the rear of the line infantry. This really is a good tactic.
Another thing that you can choose about directly attacking from forward is, in fact a better tactic if you aim to lose less cavalry of yours, is done with the use of light infantry. But we will mention it on later parts since it includes cooperation of different units. So in this part we have got how to select cavalry in order to do useful things. Light cavalry can also be an option in Napoleonic total war. Because, the higher ranks of heavy cavalry require higher rank of barracks unit. Which gives your light cavalry that you were able to recruit even since the second level of the military encampment more experience, means that the light cavalry you recruit with higher level of military encampments fight better, fire better, charge better. So, you might actually find it useful to recruit experienced light cavalry instead of inexperienced heavy cavalry. Light cavalry, when used as heavy cavalry with swords, offers a salvo of all ranks upon charging, which when considered to be in the same range of the line infantries, can cause deadly charge, as the salvo breaks the enemy formations like dynamite on the rock. And the light cavalry, can no longer be distinguished from heavy cavalry in measures of effectiveness of charge. So it is also, a good idea to use these experienced light cavalries. As another tact, you can tackle and chase enemy heavy cavalry with your light cavalry, provided you can successfully keep the distance between them.