Unlike you, I can read a 990 and do some arithmetic. That 87.9% is for "Program Expenses", which includes the charitable grants, plus those unusual salary figures, office expenses, rent, cars, utilities, etc. Your claim was "Samaritans Purse... nearly 90% of funds collected go to charity." The actual part that "go to charity" is on Line 13 Grants and similar amounts paid, which at $222,969,565 out of $585,894,450 total revenue in the 2015 990 I linked is about 38%. If you consider the Samaritans Purse employees to be proper charity cases, that might raise it another 10% or so, but still nowhere near 90%.