Whichever way you look at it, fact is the main players on both sides knew pretty well how the other side would react, namely with legal action that would consume time and funds. So either Maibaum/Wilson were briefed that a possible solution was on the horizon or Eon felt they could blow any lawsuit by McClory right out of the water. Or, third possibility, they just worked with 'no-limits' as their main guideline and were prepared to cut out or change anything sensitive retroactively. After all they've done it before with TSWLM. And landed quite a success with it.
Interestingly, Sellers' book describes the WARHEAD script by Deighton and Connery to some extend and there indeed seem to have been a number of similarities with TSWLM - such as you would expect when a script is partially a remake of a remake (YOLT) of THUNDERBALL, but also elements that must have been 'in the air' at the time, undersea base, submarines and such. TSWLM scrapped most of the references to Blofeld/SPECTRE at the eleventh hour, even going so far as to change the black uniforms of Stromberg's army to red. All in a bid to avoid the film from being delayed indefinitely as McClory threatened to do.
But in fact McClory's WARHEAD script was likewise bogged down, as it veered from its source material so drastically that you would have had difficulty recognising the book it supposedly adapted. No doubt McClory hoped to get away with the same amount of licence Eon granted themselves when filming YOLT or TMWTGG for example. By that reasoning it's easy to see how at times he hoped to base a whole series of films on his rights, he basically would have launched productions for many of Eon's films himself had he been in a position to do so.
Just as an aside, Semple's script for NSNA - which in the end followed the TB book/film closely, relatively speaking - originally was supposed to open with a jousting tournament and a subsequent fight between a killer and Bond on a modern day parking lot. It's an idea reminiscent of some of the Modesty Blaise comic strips, bizarre in a way Bond films seldom manage to be. Dick Clement, one of the script doctors tasked to try and iron out the worst in the script didn't like the opening because the whole action had Bond inside armour, not showing Connery's face till the end of the sequence. That's how the 'training mission' came into the script. After recently seeing NSNA - partially - I have to say I'd actually prefer the knight battle.