Even with two actuators the grapple would be weak. The two cylinders that roll your bucket have a combined power of much more than 3000 lbs. I don't think two actuators would work well together. If one ran slightly faster than the other it would cause problems. Hydraulic cylinders work well in parallel because they are connected to the same supply.
You can try the actuator if you want, but I think there is a reason that you don't see these things being used on tractor attachments. Adding an extra circuit is not really that big of deal. Depending on your machine you could add a 3 spool loader valve or have a remote valve installed. The manual grapple is a good lower cost idea.