I agree with JHB. This is one 'mech where its attributes don't match the job description. The speed reminds me of the British "Flower" class corvettes which weren't that much faster than the things they were assigned to escort. Not much capability to make a rapid response to incoming threats, or to close back up on your charges.
Further, the Helios really doesn't have much in the way of weaponry that helps with hitting fast targets. While a lot of that is due to the truly anemic IS pulse laser family, there isn't much here that would help with to-hit issues apart from the decent range on the gauss. The 4A version is a joke, mounting an MRM-20, which comes with an integrated to-hit penalty while simultaneously mounting a heavy weapon with worse range bands... that'll work wonders against speedy things hoping to take a bite out of your charges.
Ultimately, this is a 'mech that shows the limitations of the 60 ton class. There is the Dragon which is, in many of its forms, a higher speed thinly armoured death trap with mediocre firepower. There is the Galahad with the grace and speed of an assault 'mech to fit armour and twin gauss. There is the Lancelot which used Star League mojo to combine speed and firepower but still suffered from being a thinly armoured death trap, and later turned into a slow thinly armoured and poorly armed death trap.
Somehow, the SIC managed to fail two of the three sides of the design triangle, and barely pass the third with this design. Relatively slow, mediocre armour, and firepower that leaves quite a bit to be desired. The only weapon in this that has some modicum of ability to dictate range is the gauss. Lemme waddle over there so I can try to hit you with my 2xSRM6... hold still now.
I'd almost be tempted to load the one ton of ammo for those with either smoke or infernos. While it is unlikely to get all 12 missiles to hit, a successful strike with all 12 as infernos would work wonders against power armour, roast infantry until they are well-done, and make vehicle crews wish for napalm. As these are not streak SRM's, and there is limited ammo, their usefulness against fellow 'mechs seems dubious. 7.5 rounds of fire with a really short-ranged system, that needs to be at 120-180 meters for medium range, and that needs to be within 270 meters to even have a chance of hitting. At 3 tons/launcher and 1 ton of ammo, that's more than 10% of the 'mech's weigh devoted to a weapons system that can be out ranged by large numbers of weapons that are easily mounted on a faster chassis. I find it amusing that a private in modern infantry is given a rifle that can shoot farther than the weapons that take up more than 10% of this thing's weight.
A lot of harassment type 'mechs aren't exactly the most durable things. They tend to rely on the speed and possibly firepower sides of the triangle. In some respects, they are the torpedo boats of Battletech ground combat... move fast, hit hard, and hope like hell you don't get hit. The helios spends a bunch of mass on that gauss, which seems counter intuitive given that it's very much an overkill weapon against potential headhunters in a role that could be better served with other smaller/lighter long range weapons given the expected enemies it would face. Some damage from a volley of lighter weapons is better than no damage from a single gauss slug.
Bottom line, this thing could struggle against the better designed IS mediums. I'm pretty confident that the Uziel-2S would at least match this thing in combat. Anyway, tis late, and sleep beckons.
