Note: This is in reference to the onscreen depictions of the following characters and thus do not reflect on character descriptions from the SST novel.
1. Johnny Rico (Pvt, Cpl, Sgt, Lt) 4.5 /10 - Too much thinking with emotions than with his head. It tended to drag the flow of the story during the missions. Private Higgins the reporter claimed Rico was going to be a legend? Rico was still far from it. He eventually improved but still was too emotional to be an effective leader. Thankfully his promotions came much later in the episodes and rather sensibly as Razak promoted him to corporal during their ice-planet mission. He later became a sergeant after Sgt. Brutto got paralyzed from the waist down. To me, he seemed to be a relatively-decent sergeant, learning under Lt. Razak before the lieutenant was killed off during the San Francisco mission. Then from there was the downhill slide for Rico, going into a total brain-lock during his first command-mission at Honolulu. It took the words of Sgt. Zim to put some sense back into him so the squad could survive their mission. From that, Rico does not make the list of top-notch leaders.
2. Carmen Ibanez (Ens, Lt) 2.5 /10 - Poor pilot and an equally-poor officer. She spends more of her time trying to prove she's the best when she truly isn't. Hard-headed and unwilling to listen to common-sense advice when given, Carmen should never exceed the rank of Ensign. This is certainly true after her consistent crashing of drop ships.
3. Francis Brutto (Sgt) 4 /10 - Brutto's hostility towards others tended to be annoying. His command approach was the kind that sooner get troopers killed. Brutto's lack of clear reasoning might explain why was still a staff sergeant.
4. Marlow (Commander) 5.5 /10 - Marlow was semi-tolerable in the scenes he was involved in. His strict adherence to the rules and regulations often tended to make missions stressful on the men and women serving under his command.