To be honest, I'd rather just keep this to [HF]/[LN] with perhaps some trustworthy indies joining in on the [LN] side in the doubtful situation where [HF] outnumbers [LN].
Hackers and [HF] aren't exactly friends now after a decline in diplomatic relationships between the two parties. In fact, [HF] abhor the piracy aspect of the Lane Hackers. Only reason we're still using the 'Hacker' tag is because 4.86 and our own tag hasn't come about yet.
On an OOC perspective, more people will create more frustrating lag, as well as the fact we don't know that an indie won't try and show up in a Guardian/Scimitar/Liberator or turn up with four missiles/nukes/torpedoes. We can trust faction players more to not be douchebags about it.
I'm not slagging indies in any fashion, but the ratio of stupid indies to stupid faction players is much larger on the indie side. Hence the reason I'm hesitant to even allow [LN] indies.