For tanking, the only class with actual tanking abilities is Peltasta. They can buff their defense with Guardian (not recommended unless you don’t mind the massive damage boost for a marginal defense boost) and High Guard (very much recommended, blocking nullifies damage reliably). They also can use Swash Buckling to hold aggro, which I think is basically exclusive to them. If you want to be able to tank, get this class to at least 2nd circle, if not 3rd if you want some damage. Peltastas can do decent damage with Umbo Blow if you use it after a successful block: it’ll hit twice for double damage. With the High Guard attribute, you can do even more damage while the buff is active at the cost of your other skills taking a hit to damage. Otherwise, you can branch off into Hoplite and be an off-tank of sorts since they still use shields. Hypothetically, having 2nd rank Peltasta and then going into Hoplite can get you a lot of block bonus with the combination of High Guard and Finestra (the damage drop from High Guard will still hurt your damage overall, however). Rodelero is actually a DPS class, with Targe Smash giving a lot of DPS potential. Still, they have a lot of utility for CC with their abilities and can stun reliably with Montano. Squire is available as soon as Rank 5, but can held off if you want to develop any of the earlier classes. I actually have made a skeleton build for Peltastas on ToS Base’s skill simulator, which you can view here:
As far as stats are concerned, they don’t factor into damage too much. If you plan on using High Guard, don’t invest into DEX as you won’t be hitting criticals often anyway. Invest mainly into Strength, as you still want to be able to do some damage. CON is going to be your secondary stat to gain HP, but Swordsmen have a naturally high HP growth so it may not be necessary to have too much CON. Finally, if you feel that your low on SP a lot, then don’t be afraid to invest into SPR to help supplement your SP cap and regen. Sorry for the wall of text post, but I hope this helps. I played back in CBT2 and some of my info may be outdated, but it should still be mostly relevant.