Yes it is.
Strength is not speed, and I doubt heavy benching + dips does anything for your handspeed. I don't think it slows it down either.
Speed is motor control (antagonist inhibition, muscle co-ordination, relaxation), rate of force development, impulse, fiber type and contraction rate, the SSC and a few other things. Max strength does very little for any of those. It might increase the RFD curve a little bit at the end, but it doesn't necessarily effect the speed on the contraction. A few other important things is that if you look at the force velocity curve, speed, and especially handspeed, is at the lower end of the force spectrum:
You would want to train most of the hand speed attributes at that stage, meaning with maximal speed instead of maximal resistance. There are some contentions about intention though which does play a part. Another important point is that strength adaptions tend to be somewhat velocity specific. If you want an interesting read, although it's more barbell related, check this out:
https://www.strengthandconditioningresearch.com/perspectives/lifting-weights-fast/
When you get into something like punching it's massively more complicated what makes someone fast, than being able to lift heavy things. Motor control and contractile properties are probably two of the most important aspects but it's hard to say.
Max strength is great for a lot of things so it should be trained, and while it can have some correlation to speed, and especially power, it doesn't equal speed.
Weak is obviously relative, but one of the fastest hands in the game: