Yes, spears get penalties against sword wielding enemies, so their attack is set a bit higher, so they still slaughter horsemen, and have a chance against swordsmen, but are still at a disadvantage. Camillan and Marian principes/cohorts have +.03 to mass compared to Polybian principes, which doesn't do terribly much, but does help ever so slightly in melee. Also, the Marian cohorts come with more men than the Polybian principes and +1 to morale, at the cost of -2 armour. Yes, the Marians are more expensive due to state providing the equipment for their new prototype standing army. However, the increased manpower is what Marius set out to achieve, and this is reflected in their stats. By the time of Marius, the state could afford to spend money on the equipment, if they could only get bodies to fill the armour, and by the time that you get the Marian reforms, you should be able to fund them as well.