Keith - I'm not sure how you can compare an iron condor to the strategy you describe.
With an iron condor you are long and short equal numbers of contracts for both calls and puts. So, in the event of the market putting in a big move in either direction beyond the strike prices of your short options, the maximum loss to which you are exposed is limited to the difference between the strikes of the longs and shorts, less the net premiums taken in.
With the strategy you describe, you are long 1 x call and short 4 x calls, and long 1 x put and short 4 x puts. Therefore you are net short 3 calls and 3 puts, which means that you are open to ever increasing losses in the event of a big move outside the short strikes. In this respect, your position is a variation of a short strangle, or alternatively a 1 x 4 ratio call spread and a 1 x 4 ratio put spread, written back to back.
I've compared these positions in the pay-off diagrams shown below. The first diagram superimposes your position (blue) with a conventional iron condor (red). In the event that price moves towards the strike prices of the short positions, your position will show more profit. But in the event that prices move to more extreme positions in either direction, the losses just keep getting larger with your position, whereas they are limited with the traditional iron condor.
In the second pay-off diagram, if we compare your 1 x 4 position (red) with a conventional strangle (blue), with each position being net short 3 contracts, then your position shows slightly more profit near the strikes of the shorts, but less profit if expiry takes place in the middle of the range. Both positions show that unlimited losses can accrue in the event of a big move.
I tend to be allergic to holding large naked put positions for any length of time, so nearly always try to protect them with long puts further down. I am less worried about naked calls as there is little likelihood of the FTSE spiking 500 points higher at the open, whereas there are many reasons why a market can spike 500 points down.
Of course, I don't have the rationale behind the position you have described, and there may be times when it would be beneficial and show a better P/L profile. Perhaps you could let us know more?