i presume learning to anticipate defender can be learned.
he probably has sufficient reaction time since he can avoid tackles.
may be have him trying to tackle little shifting running backs as practice?
There are many techniques involved in blocking. Many times it's OK to get beat to one side on running plays but you absolutely can't get beat to the other side. That's how they managed to make Doug Free useful in the running game. On runs inside of Free, he would actually bait the defender into "beating" him to the outside which caused the defender to take himself out of position.
On zone stretch type runs the timing of the block is often more critical than the actual block. You just need to slow the backside defenders down by a split second.
Rico is already stronger than Hanna, Swaim or even Witten primarily because he outweighs them by about 30 pounds.
Rico physically is very similar to MartyB who was a terrific inline blocker but was too un-focused to learn the scheme while he was here. He couldn't function as a move blocker because it was more complicated schematically. He could dominate in receiving drills in practice but he couldn't seem to bring that to games, again because he didn't know the scheme and was not a good route runner.
People like to praise Witten as a great blocker, but he was nowhere close to MartyB as an inline blocker because MB was just bigger and stronger. Witten's greatness is that his blocking
relative to other top receiving TEs is very very good.