Im sorry to hear they've gone down to four. I was a great fan of their parties and my first few (as Lady Marmalade parties, no relation) were mind-blowing. I do really a good orgy. Had a couple at the Manchester Swinger clubs but to me you need a packed roomful of arms and legs, roughly even M & F, for a proper 'orgy'.
No, TPC are 5-girl parties. On occasion, when the guy numbers are not sufficient, a girl may be dropped from the line-up, as the party won't operate at a loss. I've noticed that once 7 guys are there, it hits the break-even point and there are 5 girls. Once 11 guys are there, a 6th girl is added to keep the ratio below 2:1, which is what happened at my most recent party.
These are the girl numbers and approximate guy numbers from my TPC parties this year:
18th Jan: 4 girls & 6 guys
17th Mar: 5 girls & 7/8 guys
24th Mar: 5 girls & 7/8 guys
7th Apr: 5 girls & 9/10guys
25th Apr: 5 girls & 7 guys
12th May: 5 girls & 6/7 guys
23rd Jun: 6 girls - 11/12 guys
Some guys arrive late and leave early and most guys need a break every so often, so the ratios often thin out to 1:1 at various points.