Something to that but one of the other important issues is simple . . . despite how much you might want artillery it is going to have multiple calls on it and if the front is mobile, it might also be doing it's own movement.
Add in that once it fires it becomes a 'known' target higher does not release batteries to fire willy-nilly when fighting a peer.
Yeah, that was brought up too but it wasn't necessarily peer conflict and they wanted a solution that was universal. At any rate, like MoneyLovinOgre brought up, every game has to engage with the issue that what is fun for a game isn't necessarily going to be technically, tactically, operationally or strategically realistic.
That applies to narrative as well, which accounts for why the FedCom strategy seemed to be not do much except trade combat power in a failed bid to slow down the pace of invasions until they could build a credible coalition that was able to counter-attack. I don't think that's a failure of strategy though; strategically, that is bog-standard. Among other reasons, when facing a much stronger opponent, you defend until you have the resources necessary to go over to the offensive. You certainly look for opportunities to attack in a localized sense -- either on a small-scale or temporarily -- to disrupt the enemy's own of plans, force higher costs of doing business upon them. And strategically, they made the passably decent chess moves.
Their operations weren't really too bad on paper either. The only misstep (IMO) being after learning the Clans operated under a rather strict bidding system and their own allocations were laughably under-par, the FedCom could've slashed garrisons on a lot of the planets that were hit (they were going lose anyway) in favor of placing overwhelming force on a few key planets. "I bid my full cluster" vs. "I am defending with three RCTs on this planet, are you sure about that?" Those forces could have a stronger and more-lasting delaying effect by presenting a credible threat which the Clans would have to honor by committing more forces to garrison any worlds within a jump (or two) of the hold-out worlds. But it was the execution that made things look really awful and the novels don't really get into what the combat looked on those worlds where the Clans were winning incredibly lopsided victories that would be impossible on the table or in any of the games.
Talking about stuff like Lincoln Osis taking an entire world with himself and seventy-four other Elementals, or whatever the feat was.