Of course Multibit is safer.
Bitcoin Core > 3rd party Bitcoin clients > online wallets
As you can see, online wallets are the worst decision for storing Bitcoin.
Your comparison is wrong!
Bitcoin Core = Other clients in matter of safety.
Bitcoin core verifies blocks individually to ensure that they follow the network rules. SPV clients have been proven to be quite insecure as demonstrated in the 4th July 2015 fork. Even though Bitcoin Core V 0.9.4 and below can be exposed to this threat, the risk can be migrated after upgrading.