Both Clone and Droid Army were created to give Jedi false sense of power and competence.
First consider Droid Army. Very large, but with almost useless individual troopers (especially ubiquitous B1 droid). With few exceptions ineptly lead, with unimaginative frontal assaults in geometrical formations, without any small unit tactics. Even average Jedi would destroy dozens of droids with relative ease, which lulled them in false sense of power, which was in reality miniscule compared to Sith and their assassins. Remember that even Savage Opress could kill Jedi master Adi Gallia.
And then there was Clone Army, with even more sinister role. Jedi had no formal military training, and even less knowledge how to command large formations. Yet, 20-something Anakin Skywalker become General, and Ahsoka Tano (practically a child) Commander. Clones were "programmed" to obey them without questions, but behind the scenes they certainly tried to correct worst blunders. This situations is similar to historical situation in many European armies up to WW1, where nominal commanders were from highest nobility, but troops were actually led by professional chiefs of staff and other officers with experience.
Anyway, Jedi were tricked into false belief that they are competent military leaders, well loved and respected. In fact, they more often then not served as shock troops leading the charge and nothing more. So when Palpatine finally gave Order 66, they were completely surprised and most of them were killed off without putting up much fight.
EDIT: Added some examples for claims above:
Example 1: Mace Windu leads Clone troops straight into ambush, without doing any reconnaissance although he has the means (speeders). He then charges into attack, letting Clone commander lead rest of the troops. Fortunately, Droids are too inept to take advantage, so Clones suffer casualties but are not wiped out.
Example 2: Same battle. Again Mace Windu and Obi-Wan make serious blunder, going straight into teeth of enemy defense. At 2:12 you could see that Clone troopers do not really trust judgement of their Jedi commanders. Again unnecessary loss of warship and several transport which could be avoided if they simply disembarked some distance away from objective. Again, day saved by incompetence of Droids. Btw, Droids mostly lack imagination, they have good algorithm to cover usual attack routes, but not unusual.
Example 3: Chaotic retreat. If you pay attention, you would see that actual fleet is led by Clone commander (0:35), while Jedi run off to individual combat. Jedi are good as fighters or pilots, but often don't have bigger picture in mind. Ahsoka is not only one with this trait, although as youngest she often gets scolded for mistakes of others. Droids, as usual just march and shoot, no small unit tactics.