There is no benefit to downloading from a single host in the group, nor is there a benefit in grouping files that are known to be different in the same group. LimeWire is doing you a favor by forcing you in these regards. If any 'fuzzy matching' was employed to group results together, there'd be far more corruptions on the network (and not just on your download -- on other people's downloads who are downloading from you). Forcing you to make use of other sources also helps the network, because it keeps the bandwidth requirements distributed among multiple people.