Even changing to a multi-limpet on a Size 3, still not good enough to out perform the Python or Type-8. Any smaller ship with a Enhanced Performance Thruster could most likely go faster then the Clipper. lol
I'm curious what metric you're using?
Let's assume it takes, say, 60 seconds to finish abrasion blastering all the interior surface deposits(probably way too fast, but let's make this as bad for the clipper as possible).
Then, let's assume that collector limpets can grab a fragment in, say, 20 seconds. At most you're looking at 15 fragments released initially, which means with the Clipper's 8 collectors(you forgot a surface scanner) it only takes you about 40 seconds to have already collected all the fragments initially released, and you'll have excess limpets for the remaining 20 seconds.
IE, there's no difference in time between the two. If anything, the fact the clipper can turn ~40% faster means you'll actually finish mining the core ~40% faster, as well.
You might be surprised when it comes to speed, as well. There are a few that can get way up there, but when doing so they're so mass-limited, all they can effectively do is race. When it comes to speed combined with effectiveness, the only real competition the Clipper has is the Mamba.
I'm honestly surprised how much people underrate the clipper. It's very good in the right circumstances.