An advanced rule that the majority don't play with. Planning on running closer than 7 hexes is just too dicey, when running 7 from the target is still extremely effective and doesn't require putting your connection or spotter at risk.
Not that dicey if you know where is ECM carriers are. Admittedly the issue of ECCM being an advanced rule is there, but among C3 players its actually fairly commonly used.
Your spotter should always have initiative priority for your force, and it should be easy enough to be 7 hexes away from the closest enemy unit. If you lose initiative, dropping back to be at 9 hexes still gives your forces medium range without losing your spotter to enemy fire, which is generally what happens if you get closer.
Agreed on the initiative issue, but to guarantee yourself position you need to win initiative on your opponent as well. Otherwise you could very well find yourself facing shorter ranges. Good for the rest of your lance, poor for the spotter. Better to be prepared than to assume the Random Number God favors you. Additonally, at 9 hexes your opponent is equally likely to be in middle range of your spotter. I'd rather be able to squeeze to close range and bring whole new classes of weapons to bear than to have to dance around losing much of the advantage of C3. A smart 55-tonner can stay alive for a turn or two against enemy fire without C3, it sure as all hell can do it with C3
and iJJs.
Problem being, his ECM Carrier is likely a 3/5 100 ton armor slab, and your spotter is a 55 ton XL engined skirmisher. Also, his 3/5 100 ton armor slab is probably chilling right next to the rest of it's lance, while your skirmisher is out ahead of your force to spot.
In which case your opponent has already lost. When your opponent already has a huge range modifier advantage on you by benefit of C3, there is no merit to keeping all of your mechs in a little 12 hex bubble moving at 3/5. One of the first rules of fighting C3 networks is to get your ECM inside of your opponents lines. Mobility is key. Having some heavy assaults can increase survivability, but firepower for firepwoer the C3 lance would win nearly every time by virtue of simply hitting far more often, even if they don't have as much actual firepower.
C³ is very popular on MRM units. It really shouldn't be phrased the other way. C³ makes MRMs suck less. MRMs don't do anything that C³ can't already do. With their max range of 15, C³ on MRMs is a little silly, as your gunline has to be at Gauss medium range to even have a chance to hit. There's really no need for a dedicated spotter in a MRM C³ lance. A spotter moving rapidly ahead of a MRM lance just quickly outruns the missiles it's spotting for. It's better to just move the whole lance in a loose formation so that they can give supporting fire to each other at point-blank range.
Not true at all. MRMs provide more punch for their size than almost any other weapon. They just have a pesky +1 modifier (manageable), and terrible range brackets. A very viable strategy is to use a mobile, MRM-heavy C3 lance packed to the brim with much higher damage potential than the OpFor can replicate with accuracy and using the C3 advantage to brute-force those same MRMs into an accurate bracket. It's a different type of C3 strategy than is typically used, but it's perfectly usable, and in terrain-heavier maps, often preferable to the traditional long-range strategy you describe.
Now, all that being said, I am going to say somethign you almost never hear on the internet:
you've convinced me. While I still maintain all of my above points, as well as the point that Snubbies are far-from-ideal for C3, in the specific case of the Yao Lien, I've been wooed over to your side. Crunching the numbers, and given the way it's designed to be used, it isn't easy to fit much else weapons-wise on the Yao Lien that would function at least as well without changing any of the fundamental aspects of the design (Engine, Switch to Standard JJs, etc). As such, I'm conceding that the Yao Lien works best, given the rest of its design profiel, with Snubbies. Bravo, MadCap, ya got me to admit to being wrong about something. I'm never going to hear the end of it ;)
