You can;t just arbitrarily block inclusion into blocks...the only way is if someone one out bids you in tx fee....and if they do you can wait for the next block which can be only the next second.
I am pretty sure you can decide which txs you are going to include in your block - the fee is simply to encourage to include as many as you can but if you don't want to include one or more particular txs (and instead include others) then I don't think anything can stop you.
Of course TF does help and it is likely such txs would get included in a following block, but, if we are talking about "matching an order" then a forger could simply include their own tx in preference to another (meaning that you might have just "missed out" on your buy/sell to that forger even if your tx was actually broadcast *first*).