Having a high deductible that you have not yet met is not the same as having no coverage. If you suddenly had a $100,000 medical expense, your insurance would still pay for their share of that expense. Also, any medical expenses you pay before you meet your deductible count towards your deductible.
Note that premiums for an HDHP are typically much lower than for a more traditional health insurance plan. So while you may see a bigger difference in what you spend after you receive your paycheck compared to what your husband is spending, it's important to compare the total cost, including any pre-tax money withheld from your paychecks for the employee shares of the premiums.
The HRA and HSA conflict comes from the eligibility requirements for having an HSA. An HRA acts as a form of insurance, so if you are covered by an HRA, it must be compatible with the requirements for an HSA. It sounds like your husband's employer has decided that their HRA is not compatible with an HSA so you are not eligible to be covered by it. I found this explanation useful:
Given your concerns about your deductible, it may make sense to run the numbers to comparing the total cost of your family being covered as it currently is or entirely under your plan or entirely under your husband's plan. Again, it's important to factor in any pre-tax premium payments and any changes to these that may result from including you under your husband's plan or your husband under yours. You also need to factor in expected and potential health care costs for your family and how much of that cost you would bear under the different scenarios.
Also, remember that if you have an HSA, there is no restriction on which eligible expenses you pay for using it or when they occurred (past or future) provided you were covered by an HDHP when you put the money into the HSA.