No no no, Saurus have more than one attack each. If taken outside of the Saurus Host battalion, they have 2 attacks each. They receive one from their weapons, and one from their Powerful Jaws.
If you've got 10, then they get +1 to hit per the Ordered Cohort ability. In the host, Saurus have 3 attacks!
1 from their Celestial weaponry,
2 from their Powerful Jaws (the additional one comes from their Predatory Fighter ability via Saurus Host).
So basically, every Saurus model you had was only making 2/3 of the attacks they were supposed to, and it sounds like you weren't taking advantage of the +1 to hit (at least for 1 round of combat, unless you went 2nd and lost at least one model from every unit before striking back).
The other thing about Saurus is that they have power in numbers, per their special rule. With 10, you get +1 to hit. With 20, you get +1 Attack. In a large group, you're looking at 4 attacks per model... suddenly, those re-roll 1s got a good bit better!
Under 20...
1 weapon attack (3+/3+ w/ Club, re-rolling 1s), 2 jaw attacks (4+/4+, re-rolling 1s). Each model should be scoring 1 wound.
Over 20...
2 weapon attacks (3+/3+ w/ Club, re-rolling 1s), 2 jaw attacks (4+/4+, re-rolling 1s). You may see one model scoring 2 wounds more often than not. That's pretty good.
So, yeah, Oldblood's a support guy for sure... but he really shines when you've got large blocks around him. Minimum blocks won't benefit as much because of the Ordered Cohort rule. Think of him as the Arkadon of 8th edition -- not that great, unless you take a bunch of Jungle Swarms. Then it's actually not so bad.
And yeh, skinks and terradons (SUNLEECH BOLAS!!!!) are vicious.