ARC's kits reflect on what they're trained in. The traineeship can go anywhere from one month onward and they specifically train in the areas that reflect their kit.
Grapple Hook - They train to be able to use it
Jetpack Access - They train to be able to use it
Westar - It's ARC's lore weapon and a nod to the regiment for being exclusive and hard to get into; they get their own weapon.
Other specializations; Like other regiments, ARC has sub-roles; whilst there's more, the variety reflects on other battalions sub companies so ARC are able to help train/assist if requested of tasked to.
I wouldn't call ARC a favorite of the server considering eyes are on ARC at all times now due to past situations and how some of the members have acted. I've stepped back into an advisory role in ARC to ensure that they're behaving and performing well. I can see how you may think ARC got favoritism from RHC due to both members being in/had been in ARC.
Other regiments have been trialed in the past with grapple hooks such as 91st, RC and a 187th Company and it just comes down to the fact that players who aren't correctly trained in it or who go through something like the ARC traineeship, can't be trusted with it. Unfortunately, those people have wrecked it for everyone else and it's stayed exclusive since about 2017-start of 2018 and nobody has really had a problem with it exclusive because people are able to respect and understand that ARC work hard for it plus the rest of their kit.
The slots of ARC was something touched on in last nights Commanders meeting, whilst they're a core aspect of the server and i do admit that i disagree that not all of the trainee's should have made it into the recent batch, the 15 slots is for a "what if" we get full, which in current state, it has. ARC are at the disposal of the rest of the server, current and past Commanders seem to forget that they're able to use ARC to benefit their regiment. Nothing is stopping a CO from going to the ARC CO or an Officer and asking for assistance for their regiment, ARC WILL help you if you ask. A thing that was done a long time ago was ARC veered off from working as a regiment and lent themselves out to regiments to train and advise the regiment.
As read on the ARC Star Wars Fandom page, ARC got the following; "To achieve the desired results, the Kaminoans did not apply the standard behavior correct and enhanced the primes clone's genetic sample to increase physical prowess"
Not only that, but also this image ;
I'd like to think ARC are on their way to improvement and that an image change is needed. However, i disagree with the fact that ARC don't deserve their kits and that their kits are too OP, etc.
ARC work pretty hard for what they have, whether you have seen that or not is what might sway your opinion. Maybe one of the ARC members could run you through a mock traineeship so you can see how hard it really is?
I'll reiterate, ARC needs ALOT of improvement, give them some time and I'm sure it will be fixed.