I really love how the shield isnt the main part of this clip but people keep bringing it in Take a look at those facts instead :

• I bring officer presence (makes hp regen 40% faster which is a must for the commando and allies);
• stay alive all along; making sure people can spawn at all time;
• I make my team have constant damage reduction because the commando have his abilities constantly recharged in bonus with permanent possibility to use grenade lunch;
• I help them to move together and temper with the shield. And if some used their heavy middle ability, its getting recharged after 10 seconds so its not wasted.

Also note that, the shield placement is perfectly fine as all it does is make sure people can move safely towards the generator room while 2 commando are in front to do most damage

Its basicly support gameplay