If the Andorians are building their own Excaliburs, then that would be a wild swerve from when we were told that the member fleets were starting to lose the ability to conduct expeditionary warfare in this era, but it's not impossible they since decided to re-arm? I suppose it is an elegant way to escape the trap we've constructed for ourselves here without violating the already-established number of Excalibur-class ships that got built.
However you may feel about the merits of the Excalibur, the quest to-date has always shown Starfleet having to match more expensive heavy warships with cheaper bread-and-butter combatants, and this is in fact backed up by the numbers of ships we know are produced for this conflict. It's simply how things have always been done in the Quest, whether for cost-effectiveness concerns, sufficient numbers of hulls, or for whatever other reasons.
If you want to argue with someone, argue with Sayle and tell him that Starfleet should build more of them and less Newtons, rather than me for simply being the messenger.