Clinton could have made the same strong case without making it about Obama. For instances, he could have spoken like he did in 2012, when Obama was on the ticket. He could have moved away from Obama himself to defending what Obama and the Democrats did on the economy and on health care.
Arkansas is one of the states that finally did move to expand Medicaid. This means that many people who never had health insurance have it now. Arkansas is an extremely poor state - so this likely was a bigger deal there than in states where fewer people are below that threshold.
As to the economy - we all have seen the charts on unemployment and what Obama has done - in spite of the Republicans - is remarkable. He could actually have argued, that just like he did, Obama greatly improved the economic situation from where it was when he entered office.
Instead, this looks like another attempt to distance Clinton from Obama. If HRC had not distanced herself on fp - even giving the Republicans a gift when she suggested that not doing more in Syria led to ISIS - I don't think I would have had any sensitivity here. In addition, this plays into the view that to the Clintons, loyalty is extremely important, but it is defined in only one direction -- to them. I doubt the Clintons would have been happy with a cabinet member who did this to Bill while he was still in office.