Granted, the hand below is an extreme example, however the risk of blocking your partner's lone call is very real.
I am the dealer, sitting in South position, and have just turned up the jack of clubs. My partner(N) decides it's a good idea to order up the right.
Yes, we made two points but my partner never took a trick.
While, as a partner, it is correct to order up the right when holding three trump, ordering with two is not. The only time you should even consider ordering with only two is with a partner that has shown a reluctance to try lone calls or even name trump. Yes, this is an extreme example, but the reality is that by ordering you will prevent your partner from making a successful lone. If your partner has even a little euchre experience, the only time he wouldn't pick-up the right would be when he holds no matching cards and basically a complete junk hand. In such a case, there is a possibility that you are going to be euchred.
You have to trust your partner's ability to bid the hand correctly.