Hi
As far as I know, and I stand to be corrected, if you have received an invitation to apply, you have 60 days to respond/accept the invitation. If during this time, you get an invite for 189, then I think it would be okay to go for the 189. But if it is past the 60 days and you do not get invited for the 189, then you will lose the 190 too.
It would seem that it is going to be a long while before Accountants get back on again. Safest thing is to accept the 190 and apply for the visa. If you have the finances and the 189 comes later, you can apply for the 189 visa. The last visa granted supersedes the others. Please note that I am not an agent, the information I have provided here is from what I have read. Please also check with an agent before making any decisions.