Yes, G L Wilde, head of Rolls-Royce's 'design department' wrote an article (maybe for a conference? - I found it in aero 9/1961) on 'Engines for VTOL aircraft'. The Draken lookalike is described as a strike aircraft (several other configurations were shown, e. g. attacker with swept wing, different tactical transports with 20 or 32 lift engines - a good idea by RR to increase the production ;D ).
Interesting. Usually the "Draken like" plane had twelve lift engines, not only four.