You can amend that by buying a slightly shorter stem, the staff should have fitted you correctly without resorting to buying more component to make it fit you better.
Shorter stem will make the bike feel twitchier, but won't make it so, it's something you can get used to in no time.
It sound like you'll benefit from the Secteur one size smaller than your Allez, the other advantage of the Secteur is that the handlebar is higher than the Allez, meaning the position will feel similar, just shorter with more seatpost showing (more comfortable).
You can amend that by buying a slightly shorter stem, the staff should have fitted you correctly without resorting to buying more component to make it fit you better.
Shorter stem will make the bike feel twitchier, but won't make it so, it's something you can get used to in no time.
It sound like you'll benefit from the Secteur one size smaller than your Allez, the other advantage of the Secteur is that the handlebar is higher than the Allez, meaning the position will feel similar, just shorter with more seatpost showing (more comfortable).