I still don't understand the complaints from people who consider themselves separate from all manner of story activity, but complain when they're not invited to story activity.
Going back to the topic at hand, though. It takes a few
years to branch across every Path and unlock all those powers. So having a bloodline that is strictly one piece of the six, makes them a specialised but also limited team. Your powers make you naturally aligned to some tasks and your notoriety is also affected by your base path.
When it comes to the Shadow Vamps, I've noticed that they do take longer to heal than others. When Levi was young, before I increased his healing stat to 20 (which absorbed around 6 level ups), his wounds averaged 3 days. It was a giant pain. Now they average 1 or 2. So he's still at a slight disadvantage and it would be even worse if he couldn't quickly branch to the Necros and learn those healing powers. A Telepath would have a much harder time accessing those same powers because of how far away they are, so, time and effort is required to balance the differences between the Paths when you're looking at certain activities.
Oh and I've been playing, off and on, for 5 years and Levi has only just been able to unlock the Telepath ability of Appraisal. The amount of PXP this involved was incredible. If you consider he had to go from Shadow to Telepath. But, you can pay real money to shorten the time by buying PXP orbs. There are ways around a lot of things, but that's a helpful crux toward balancing the Paths with proof in point meaning that they're different.
If you were going to do a team raid, you generally look for characters who have a variety of powers and skills. A team of 5 Necromancers who are a few month old would be totally different to a group of 5 mixed Paths of the same age.
The RP factor is strong, but this is a game with a storyline and a strong Roleplaying element. So, of course having a team of only Necros would heavily affect the Roleplay element. That doesn't make it ONLY roleplay affecting.
David has tried to balance the grid as much as possible to avoid instances where one Path dominated, but I do believe they still have their unique abilities in game.
It would be nice to hear more detailed feedback on this debate aside from "because I think that way" and "That's what blood packs are for". I always encourage opportunities to learn something new.