Haven’t seen much of Ajagba due to him fighting on American networks but the other two are both heavy handed and punch through their targets despite having slow hand speed.
Joyce I'd say is a bit slower than the other too, but he's also more agile than the other too. Ajagba's jab is not too slow he can snap it out sometimes but when he throws in combination he's awfully slow. Foreman could still throw the odd fast right hand when he threw it straight we saw that a few times in the Moorer fight.
You need to see Ajagba and old Foreman do their practice. Then lookout for certain matches to see how good they can be at their best.