For a single-engine solution to AW.406 I would look at Dassault’s studies for inspiration and use a Medway instead of a TF-306E (which had 23,000lbs thrust).
I believe the design requirements for a balanced interceptor / low altitude strike aircraft were not that far off… more detail in the attached paper below.
Below is how Dassault viewed the options as of 1966/67… the variable geometry Mirage G was the clear winner vs. the Mirage F2/F3 and delta or VTOL options.
Variable geometry interceptor/strike aircraft
(Mirage G, 1x TF-306 23,000lbf thrust, 9t empty weight)
Interceptor mission (with guns + 1 AAM):
Climb to M2.2/50,000ft: <5min
CAP time: 2.7hrs, with fuel for M2.2 intercept at 50,000ft and 10% reserves
Dash speed: M2.5
Strike mission (with 1 nuclear bomb):
Penetration range: 390NM LO-LO with 80nm dash at 600kts / M0.9, 5min time on target, and 10% reserves
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