You get one tone from the first developer and another tone from the positive image in the second developer. If bromide is the only difference, then it is due to bromide, but if there are changes in Metol and / or HQ, then all bets are off. Same for Sulfite. Even BTAZ or PMT can alter the image tone as is well known.

You probably cannot reverse the order of the tones though unless you add a wash step before the second developer such that all of "toning" chemistry A is removed before developer B is entered and the flash is done.