You're partially right, but economy rate is somewhat more significant in ODI's than strike rate or average...not to the extent that Gavin Larsen>Brett Lee, as Richard has argued, but more important nonetheless.As long as his economy rate isn't ridiculous, I think it matters very little when he is fulfulling his role as a strike bowler absolutely perfectly. What's he average, 2 and a half wickets every 10 overs? That's outstanding.
Also, an economy rate of 5.46 is bordering on the ridiculous (IMO, anything >5 is still a touch too high). The fact that Tait has been known to bowl spells of 10 overs for 26 and 68 () respectively highlights his inconsistency, too.