FWIW, here's an interesting excerpt from Schneider's first draft script dated June 21, 1966. The below takes place in the briefing room and is at a time that's before the Romulans fire their weapon on the Enterprise. (Btw, for you purists, I didn't bother with script format... because.)
KIRK
Mr. Spock, let's have the comparison.
SPOCK
...We have the possible advantage of better detection equipment. Several times their maximum speed... They have an invisibility screen; we're keeping tabs only by our most sophisticated sensors which, as you know, can only indicate general areas of space disturbance. They also have a new type of ordinance - range may be equal to our phasers - power presently unmeasured... except we know it is staggering - enormous - beyond anything we've got.
There is a deep, pregnant silence from the assemblage.
DOCTOR
(clearing his throat)
Then our only real edge is speed. Even there, how can we assume they are now traveling at max?
KIRK
Because we've pursued for ten minutes - holding relative positions, to make their Captain believe he has a false echo on his instruments.
DOCTOR
Any reason to think it's working?
KIRK
Some. He's been testing with zig-zag maneuvers, and reduced speeds. But always coming back up to this speed, always back on 973...
(half to himself)
...Which is precisely what I would do were I in his place - and had to get home fast as I could...
FWIW.