I don't think it's fair to lump the two groups together. While I will agree that both groups are petty and immature, I think there is a demonstrable difference in the zeal and desire of birthers versus whoever added the brown noser tidbit to Wikipedia.
The first difference is intent. The Wikipedia entry was made before this announcement, as opposed to the birther's claims which didn't surface until the President was at least the presumptive nominee. The Wikipedia entry doesn't reflect well for Representative Ryan. The supposed claim by the birthers would, if it had any veracity at all (hint: it doesn't and never did) disqualify him completely. The intent is not merely to smear the President, as one might think the claim about Ryan is intend, but to disqualify him for his mere personage.
The second difference is zeal. Again, this is merely an edit to a page made well before Ryan was involved directly in the race for President. Meanwhile, the birthers have been at this for the last 4 years.No amount of contrary evidence has stopped the birthers. They've filed lawsuits in multiple states and wasted countless tax dollars on their nonsense.
The third difference is hate. Birthers are more of a hate group than anyone who would put this on Mr. Ryan's page. Nobody likes a brown noser, unless perhaps its your rump causing that nose to be brown. Meanwhile, birthers are hateful racists that are determined to "other" anyone who does not fit the "traditional" mold for American leadership. As others have stated, Mr. Romney's citizenship was never questioned. Neither was Mr. McCain's. The difference is that some believe there should be an unconstitutional religious test for the presidency and that President Obama's skin isn't the right color. Yes, racism is childish and stupid, but it is a particularly hurtful type of childishness and stupidity. There is not a history of enslaving, killing, raping, and dehumanizing brown nosers, instead we promote them to middle management.
The last difference is whom is advancing the issue. The person who put this on Wikipedia did not do so as part of a conspiratorial movement. For all we know it was an old classmate poking fun. There was no fanfare about this until someone removed it for political reasons. Thus, the ones seeking to deny Ryan's status as a brown noser are making this into an issue, rather than the ones presenting that status. This is very different than birthers, who advanced the issue and were generally ignored until their petty cries and expensive lawsuits became too annoying (and the President saw a chance to win a news cycle which might have otherwise gone to other things). So far the ones being petty in this issue are the Ryan supporters who think this matters.
So, sure, you can say the two groups have similar properties but I think lumping them together denies how much dumber birthers truly are.