I don't believe they had to change it to Circular Hunt to make the same number show on all 3 lines.
Terminal Hunt can actually mean 2 different things, which may or may not both be designated for the same hunt group.
1 The inbound calls begin with line 1 and progress to the last line in the hunt group and the hunt 'terminates' when the incoming call either goes to an available line position, or busy signal if there are no available line positions.
2. Lines are 'Terminals' with consecutive TERMINAL Numbers that are all assigned to the same PHONE number. i.e. xxx-1321, terminals 1, 2, and 3. The TERMINAL numbers are for bookkeeping purposes. If the repair guy has a report that xxx-1321 is open, he has to know which TERMINAL so that he can work on the correct TERMINAL.
And now you know more than you wanted. smile John C.

When I was young, I was Liberal. As I aged and wised up, I became Conservative. Now that I'm old, I have settled on Curmudgeon.