I agree with Walter and Joe,
if uke gifts me with a grab, that takes one of his limbs out of his attacking arsenal, which is great news for me
As tori I will then do everything I can to maintain that sticky connection as I
know where that limb of uke's is, leaving me free to concentrate on being out of range of the rest of him.
Many tori tend to mis-time their movements and lose this connection, either not allowing it to happen in the first place, or ripping themselves clear of the grip. All this does is to leave tori open to another strike, which I'm happy to provide
Not everyone agrees with this and thinks that it's uke's job to hang on, no matter how hard tori makes it for them
As a person with child sized hands I can't wrap my fingers around large wrists either, but I don't attack with my hands, I attack with my centre
through my hands and use my intention to drive the attacking force. This is usually enough for me to make tori's job difficult if he doesn't blend correctly
Ruth