I've found that, if you get dogs that are similar in energy-output and os similar age, two is better than one.
But... I did that a few years ago, when we rescued our pbt/rhodesian ridgeback mix, Rufus. At the time, he was supposed to be two, and my mostly-large terrier Heinz57, Midnight was still very playful & young-acting.
Now, Midnight is about to turn 13 and he's no longer interested in too much rough play, but Rufus, depsite being about 7 (the vet apparently was wrong on Rufus' age at her original guesstimate), still wants to play 24/7.
I have to keep them separated, these days, coz Rufus never knows when to leave Midnight alone ..... and, depsite being smaller, older, and a predominately terrier mix, Midnight has torn Rufus (a pit mix) apart a few times, just in attempt to enforce his leave-me-the-f-alone attitude.
After having to take Rufus for a few unhappy visits to the pricy Vet Emergency Clinic, I no longer let them two of them out together, at the same time. Not unsupervised, anyway.