That is not true. If given the choice, Steele would rather keep bleeding the UEF dry - that would be the wiser strategy for the GTVA if they could afford the time, one that ensures victory with minimal losses. That is the exact strategy Severanti has been employing for 18 months and the results of this strategy enabled Steele to plow through 3rd Fleet with minimal resistance.
But the GTVA can't afford to follow this wise but lengthy strategy. Shivan incursion could happen at any time. Civil unrest is brewing at home. And last but not least, the Project, whatever it is, is getting closer to completion. The Tev must end the war as quickly as possible. Their decision to deploy four more battlegroups is clearly a calculated, but major gamble born of desperation to end the war now, and because of that they will sustain losses. Because UEF logistical collapse is still weeks/months away. Because Byrne has saved the near entirety of 1st Fleet's strength. Because Netreba is barely bloodied, and that Calder is more than willing to hit where it will hurt the most, and still able to do so. And because the Fedayeen are now on the loose.
Steele's is using more agressive tactics to end the war swiftly, but this does not come without a price. It is, in fact, a massive gamble. Steele sustained significant losses during Earth' Blitz, and four more battlegroups or not, genius or not, another attack on Earth as predicted by Cassandra will lead to more losses. What remains to be seen is how large those losses will be.