i agree, reason being yes the kyuubis has had not only its chkra halfed, but its soul. the death reaper rips the soul from the body. and the kyuubi actually decreased in size GREATLY , i actually think the kyuubi will be smaller than hachibi , and by assumption ...weaker in strength.
to the people disagreeing, think of it this way: the bijuus power is measure in tails correct. the kyuubi originally had 9/10 <-denominator being the total(juubi). then if that was halfed it will be 4.5/10 . if your saying that the kyuubi is still stronger than the hachibi after having its self halved; then your basically saying the kyuubi strength is nearly double what the hachibi has, at first glance its ok but it would mean the hachibi has double what the 7 tails has and then the 7 tails has double what the 6 tails does and so on and so on. THIS doesnt make sense because the five tails was clearly able to put up a good fight against the 8 tails like the gap between power was small.