Just had a thought ref the Tiger interim replacement.
The AH-1Z would be a step backwards.
The AH-64E is both more complex and difficult to maintain than Tiger, while still being inferior in a number of areas.
An upgraded Tiger has its advantages but there are insufficient airframes to meet the stated requirement.
A type already in service or planned for service could be an option as an interim replacement for, or supplement to Tiger.
Whatever is selected as a light helicopter to support SOF in 6AVN comes to mind. The issue here would be lack of range and payload.
A version of another type in service could be suitable supplement to an upgraded Tiger, i.e. MRH or Romeo, with the type still being of use once the new generation of helo arrives in the 2030s.
MRH is probably too large but a CSAR version could be suitable.
Romeo would likely not be suitable but Sierra could well fit the bill.